Biological materials related to CXCR7

ABSTRACT

The present invention relates to particular polypeptides, nucleic acids encoding such polypeptides; to methods for preparing such polypeptides; to host cells expressing or capable of expressing such polypeptides; to compositions and in particular to pharmaceutical compositions that comprise such polypeptides, for prophylactic, therapeutic or diagnostic purposes.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No. 13/073,044, filed on Mar. 28, 2011, which issued as U.S. Pat. No. 8,937,164, which claims the benefit under 35 U.S.C. §119(e) of U.S. provisional application No. 61/318,000, filed Mar. 26, 2010, the disclosures of which are each incorporated by reference herein in their entirety.

FIELD OF THE INVENTION

The present invention relates to biological materials related to CXCR7 and more in particular to polypeptides, nucleic acids encoding such polypeptides; to methods for preparing such polypeptides; to host cells expressing or capable of expressing such polypeptides; to compositions and in particular to pharmaceutical compositions that comprise such polypeptides, for prophylactic, therapeutic or diagnostic purposes.

BACKGROUND OF THE INVENTION

Although it is suggested in the art i) that the blockage of CXCR7 employed along with CXCR4 blockage may be useful for the treatment of SDF-1-dependent tumor progression and metastasis (R B Maksym et al., 2009, The role of stromal-derived factor-1—CXCR7 axis in development of cancer, European Journal of Pharmacology, 625 (1-3), pages 31-40) and ii) that some small molecular inhibitors, such as CCX733 or CCX266, siRNA and blocking antibodies (clones 11G8, 9C4 see e.g. US20070167443; clone 358426 (R&D Systems); 8F11 (Biolegend)), may be useful for therapeutic interference with CXCR4-mediated activation of integrins (T N Hartmann et al., 2008, A crosstalk between intracellular CXCR7 and CXCR4 involved in rapid CXCL12-triggered integrin activation but not in chemokine-triggered motility of human T lymphocytes and CD34+ cells, Journal of Leukocyte Biology, 84, pages 11301140), the biology of CXCR7 is still poorly understood since the mechanism(s) of action through which CXCR7 acts is unclear since i) it may act as a kind of decoy or signalling receptor depending on cell type—R M Maksym et al., supra and since ii) the interplay between ITAC and SDF-1 binding to CXCR7 is unclear.

The identification of selective therapeutically effective anti-CXCR7 agents is not only challenging because of its poorly understood biology (such as e.g. mechanism of action e.g. of the potential agonists CCX733 or CCX266 versus antagonists, interplay with CXCR4, recognition of important epitopes, cross-reactivity of the compounds CCX733 or CCX266 and associated toxicity), it is also acknowledged in the art (see e.g. Naunyn-Schmied Archives Pharmacology 379: 385-388) that the generation of an anti-GPCR therapeutic agent such as an anti-CXCR7 agent is difficult since i) the native conformation of active CXCR7 in cancer cells is not exactly known, since ii) it is expected that CXCR7 shows low immunogenicity (due to a limited number of extracellular surface exposed amino acid residues that are in addition very conserved, e.g. mouse-human CXCR7 is 96% homologues).

Furthermore, compounds (CCX733, CCX754) selectively blocking binding of CXCL11 and CXCL12 to CXCR7 function like chemokine ligands with respect to homodimerization, i.e. enhance CXCR7 homodimerization by 2.5 to 3.5 fold with significant increases (P<0.05) first detected at 10 and 100 nM (K E Luker et al., 2009, Imaging chemokine receptor dimerization with firefly luciferase complementation, FASEB journal, 23, pages 823-834).

Targeting serum albumin to extend the half-life of biological molecules such as e.g. immunoglobulin single variable domains has been described e.g. in WO2008/028977.

The generation of a conventional anti-CXCR7 antibody has been described e.g. in WO2006116319 for conventional antibodies 11G8, 6E10 and in Zabel et al. for conventional antibody 8F11 (Zabel et al., 2009, Elucidation of CXCR7 mediated signalling events and inhibition of CXCR4 mediated tumor cell transendothelial migration by CXCR7 ligands. J Immunol.; 183 (5):3204-11). However, it is unclear at present whether these or similar antibodies are suitable for a medical application

SUMMARY OF THE INVENTION

The art is in need of potent anti-CXCR7 agents that can credibly explore and establish the medical potential of this target and, furthermore, is in need of diagnostically, preventatively, and/or therapeutically suitable anti-CXCR7 agents such as provided herein.

Immunoglobulin sequences, such as antibodies and antigen binding fragments derived therefrom (e g immunoglobulin single variable domains) are used to specifically target their respective antigens in research and therapeutic applications. The generation of immunoglobulin single variable domains such as e.g. VHHs may involve the immunization of an experimental animal such as a Llama, construction of phage libraries from immune tissue, selection of phage displaying antigen binding immunoglobulin single variable domains and screening of said domains and engineered constructs thereof for the desired specificities (WO 94/04678). Alternatively, similar immunoglobulin single variable domains such as e.g. dAbs can be generated by selecting phage displaying antigen binding immunoglobulin single variable domains directly from naïve or synthetic libraries and subsequent screening of said domains and engineered constructs thereof for the desired specificities (Ward et al, Binding activities of a repertoire of single immunoglobulin variable domains secreted from Escherichia coli, Nature, 1989 Oct. 12; 341 (6242): 544-6); Holt et al., Trends Biotechnol., 2003, 21(11):484-490; as well as for example WO 06/030220, WO 06/003388 and other published patent applications of Domantis Ltd.).

The present invention relates to particular polypeptides that comprise or more preferably essentially consist of i) a first building block consisting essentially of one or more (preferably one) immunoglobulin single variable domain(s), wherein said immunoglobulin single variable domain(s) is(are) directed against CXCR7 and in particular against human CXCR7; and ii) a second building block consisting essentially of one or more (preferably one) immunoglobulin single variable domain(s), wherein said immunoglobulin single variable domain(s) is(are) directed against serum albumin and in particular against human serum albumin (and even more preferably wherein said immunoglobulin single variable domain is Alb8 (as herein defined)). Furthermore, the invention also relates to nucleic acids encoding such polypeptides; to methods for preparing such polypeptides; to host cells expressing or capable of expressing such polypeptides; to compositions and in particular to pharmaceutical compositions that comprise such polypeptides, nucleic acids and/or host cells; and to uses of such polypeptides, nucleic acids, host cells and/or compositions for prophylactic, therapeutic or diagnostic purposes. Other aspects, embodiments, advantages and applications of the invention will become clear from the further description herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The figures are illustrative only and are not required for enablement of the invention disclosed herein.

FIG. 1 shows an SDF1 competition experiment using FACS.

FIG. 2 shows an 11G8 competition experiment using FACS.

DESCRIPTION OF THE INVENTION Definitions

-   a) Unless indicated or defined otherwise, all terms used have their     usual meaning in the art, which will be clear to the skilled person.     Reference is for example made to the standard handbooks mentioned in     paragraph a) on page 46 of WO 08/020079. -   b) Unless indicated otherwise, the term “immunoglobulin single     variable domain” is used as a general term to include but not     limited to antigen-binding domains or fragments such as V_(HH)     domains or V_(H) or V_(L) domains, respectively. The terms     antigen-binding molecules or antigen-binding protein are used     interchangeably and include also the term Nanobodies. The     immunoglobulin single variable domains further are light chain     variable domain sequences (e.g. a V_(L)-sequence), or heavy chain     variable domain sequences (e.g. a V_(H)-sequence); more     specifically, they can be heavy chain variable domain sequences that     are derived from a conventional four-chain antibody or heavy chain     variable domain sequences that are derived from a heavy chain     antibody. Accordingly, the immunoglobulin single variable domains     can be domain antibodies, or immunoglobulin sequences that are     suitable for use as domain antibodies, single domain antibodies, or     immunoglobulin sequences that are suitable for use as single domain     antibodies, “dAbs”, or immunoglobulin sequences that are suitable     for use as dAbs, or Nanobodies, including but not limited to V_(HH)     sequences. The invention includes immunoglobulin sequences of     different origin, comprising mouse, rat, rabbit, donkey, human and     camelid immunoglobulin sequences. The immunoglobulin single variable     domain includes fully human, humanized, otherwise sequence optimized     or chimeric immunoglobulin sequences. The immunoglobulin single     variable domain and structure of an immunoglobulin single variable     domain can be considered—without however being limited thereto—to be     comprised of four framework regions or “FR's”, which are referred to     in the art and herein as “Framework region 1” or “FR1”; as     “Framework region 2” or “FR2”; as “Framework region 3” or “FR3”; and     as “Framework region 4” or “FR4”, respectively; which framework     regions are interrupted by three complementary determining regions     or “CDR's”, which are referred to in the art as “Complementarity     Determining Region 1” or “CDR1”; as “Complementarity Determining     Region 2” or “CDR2”; and as “Complementarity Determining Region 3”     or “CDR3”, respectively. It is noted that the terms Nanobody or     Nanobodies are registered trademarks of Ablynx N.V. and thus may     also be referred to as Nanobody® and/or Nanobodies®). -   c) Unless indicated otherwise, the terms “immunoglobulin sequence”,     “sequence”, “nucleotide sequence” and “nucleic acid” are as     described in paragraph b) on page 46 of WO 08/020079. The term     Nanobody is also as defined in WO 08/020079, and as described     therein generally refers to an immunoglobulin heavy chain variable     domain that has the functional and/or structural characteristics of     a V_(HH) domain (e.g. a V_(H) domain from the “heavy-chain only”     antibodies that occur in Camelids), and as such may in particular be     a (native) V_(HH), a humanized V_(HH) or a camelized V_(H), such as     a camelized human V_(H). -   d) Unless indicated otherwise, all methods, steps, techniques and     manipulations that are not specifically described in detail can be     performed and have been performed in a manner known per se, as will     be clear to the skilled person. Reference is for example again made     to the standard handbooks and the general background art mentioned     herein and to the further references cited therein; as well as to     for example the following reviews Presta, Adv. Drug Deliv. Rev.     2006, 58 (5-6): 640-56; Levin and Weiss, Mol. Biosyst. 2006, 2(1):     49-57; Irving et al., J. Immunol. Methods, 2001, 248(1-2), 31-45;     Schmitz et al., Placenta, 2000, 21 Suppl. A, S106-12, Gonzales et     al., Tumour Biol., 2005, 26(1), 31-43, which describe techniques for     protein engineering, such as affinity maturation and other     techniques for improving the specificity and other desired     properties of proteins such as immunoglobulins. -   e) Amino acid residues will be indicated according to the standard     three-letter or one-letter amino acid code. Reference is made to     Table A-2 on page 48 of the International application WO 08/020079     of Ablynx N.V. entitled “Immunoglobulin single variable domains     directed against IL-6R and polypeptides comprising the same for the     treatment of diseases and disorders associated with 11-6 mediated     signalling”. -   f) For the purposes of comparing two or more nucleotide sequences,     the percentage of “sequence identity” between a first nucleotide     sequence and a second nucleotide sequence may be calculated or     determined as described in paragraph e) on page 49 of WO 08/020079     (incorporated herein by reference), such as by dividing [the number     of nucleotides in the first nucleotide sequence that are identical     to the nucleotides at the corresponding positions in the second     nucleotide sequence] by [the total number of nucleotides in the     first nucleotide sequence] and multiplying by [100%], in which each     deletion, insertion, substitution or addition of a nucleotide in the     second nucleotide sequence—compared to the first nucleotide     sequence—is considered as a difference at a single nucleotide     (position); or using a suitable computer algorithm or technique,     again as described in paragraph e) on pages 49 of WO 08/020079     (incorporated herein by reference). -   g) For the purposes of comparing two or more immunoglobulin single     variable domains or other amino acid sequences such e.g. the     polypeptides of the invention etc, the percentage of “sequence     identity” between a first amino acid sequence and a second amino     acid sequence (also referred to herein as “amino acid identity”) may     be calculated or determined as described in paragraph f) on pages 49     and 50 of WO 08/020079 (incorporated herein by reference), such as     by dividing [the number of amino acid residues in the first amino     acid sequence that are identical to the amino acid residues at the     corresponding positions in the second amino acid sequence] by [the     total number of amino acid residues in the first amino acid     sequence] and multiplying by [100%], in which each deletion,     insertion, substitution or addition of an amino acid residue in the     second amino acid sequence—compared to the first amino acid     sequence—is considered as a difference at a single amino acid     residue (position), i.e. as an “amino acid difference” as defined     herein; or using a suitable computer algorithm or technique, again     as described in paragraph 0 on pages 49 and 50 of WO 08/020079     (incorporated herein by reference).     -   Also, in determining the degree of sequence identity between two         immunoglobulin single variable domains, the skilled person may         take into account so-called “conservative” amino acid         substitutions, as described on page 50 of WO 08/020079. Any         amino acid substitutions applied to the polypeptides described         herein may also be based on the analysis of the frequencies of         amino acid variations between homologous proteins of different         species developed by Schulz et al., Principles of Protein         Structure, Springer-Verlag, 1978, on the analyses of structure         forming potentials developed by Chou and Fasman, Biochemistry         13: 211, 1974 and Adv. Enzymol., 47: 45-149, 1978, and on the         analysis of hydrophobicity patterns in proteins developed by         Eisenberg et al., Proc. Natl. Acad Sci. USA 81: 140-144, 1984;         Kyte & Doolittle; J Molec. Biol. 157: 105-132, 1981, and Goldman         et al., Ann Rev. Biophys. Chem. 15: 321-353, 1986, all         incorporated herein in their entirety by reference. Information         on the primary, secondary and tertiary structure of Nanobodies         is given in the description herein and in the general background         art cited above. Also, for this purpose, the crystal structure         of a V_(HH) domain from a llama is for example given by Desmyter         et al., Nature Structural Biology, Vol. 3, 9, 803 (1996);         Spinelli et al., Natural Structural Biology (1996); 3, 752-757;         and Decanniere et al., Structure, Vol. 7, 4, 361 (1999). Further         information about some of the amino acid residues that in         conventional V_(H) domains form the V_(H)/V_(L) interface and         potential camelizing substitutions on these positions can be         found in the prior art cited above. -   h) Immunoglobulin single variable domains and nucleic acid sequences     are said to be “exactly the same” if they have 100% sequence     identity (as defined herein) over their entire length. -   i) When comparing two immunoglobulin single variable domains, the     term “amino acid difference” refers to an insertion, deletion or     substitution of a single amino acid residue on a position of the     first sequence, compared to the second sequence; it being understood     that two immunoglobulin single variable domains can contain one, two     or more such amino acid differences. -   j) When a nucleotide sequence or amino acid sequence is said to     “comprise” another nucleotide sequence or amino acid sequence,     respectively, or to “essentially consist of” another nucleotide     sequence or amino acid sequence, this has the meaning given in     paragraph i) on pages 51-52 of WO 08/020079. -   k) The term “in essentially isolated form” has the meaning given to     it in paragraph j) on pages 52 and 53 of WO 08/020079. -   l) The terms “domain” and “binding domain” have the meanings given     to it in paragraph k) on page 53 of WO 08/020079. -   m) The terms “antigenic determinant” and “epitope”, which may also     be used interchangeably herein, have the meanings given to it in     paragraph 1) on page 53 of WO 08/020079. -   n) As further described in paragraph m) on page 53 of WO 08/020079,     an amino acid sequence (such as an antibody, a polypeptide of the     invention, or generally an antigen binding protein or polypeptide or     a fragment thereof) that can (specifically) bind to, that has     affinity for and/or that has specificity for a specific antigenic     determinant, epitope, antigen or protein (or for at least one part,     fragment or epitope thereof) is said to be “against” or “directed     against” said antigenic determinant, epitope, antigen or protein. -   o) The term “specificity” has the meaning given to it in     paragraph n) on pages 53-56 of WO 08/020079; and as mentioned     therein refers to the number of different types of antigens or     antigenic determinants to which a particular antigen-binding     molecule or antigen-binding protein (such as a polypeptide of the     invention) molecule can bind. The specificity of an antigen-binding     protein can be determined based on affinity and/or avidity, as     described on pages 53-56 of WO 08/020079 (incorporated herein by     reference), which also describes some preferred techniques for     measuring binding between an antigen-binding molecule (such as a     polypeptide of the invention) and the pertinent antigen. Typically,     antigen-binding proteins (such as the immunoglobulin single variable     domains, and/or polypeptides of the invention) will bind to their     antigen with a dissociation constant (K_(D)) of 10⁻⁵ to 10⁻¹²     moles/liter or less, and preferably 10⁻⁷ to 10⁻¹² moles/liter or     less and more preferably 10⁻⁸ to 10⁻¹² moles/liter (i.e. with an     association constant (K_(A)) of 10⁵ to 10¹² liter/moles or more, and     preferably 10⁷ to 10¹² liter/moles or more and more preferably 10⁸     to 10¹² liter/moles). Any K_(D) value greater than 10⁴ mol/liter (or     any K_(A) value lower than 10⁴ M⁻¹) liters/mol is generally     considered to indicate non-specific binding. Preferably, a     monovalent immunoglobulin single variable domain of the invention     will bind to the desired antigen with an affinity less than 500 nM,     preferably less than 200 nM, more preferably less than 10 nM, such     as less than 500 pM. Specific binding of an antigen-binding protein     to an antigen or antigenic determinant can be determined in any     suitable manner known per se, including, for example, Scatchard     analysis and/or competitive binding assays, such as     radioimmunoassays (RIA), enzyme immunoassays (EIA) and sandwich     competition assays, and the different variants thereof known per se     in the art; as well as the other techniques mentioned herein. As     will be clear to the skilled person, and as described on pages 53-56     of WO 08/020079, the dissociation constant may be the actual or     apparent dissociation constant. Methods for determining the     dissociation constant will be clear to the skilled person, and for     example include the techniques mentioned on pages 53-56 of WO     08/020079. -   p) The half-life of an amino acid sequence, compound or polypeptide     of the invention can generally be defined as described in     paragraph o) on page 57 of WO 08/020079 and as mentioned therein     refers to the time taken for the serum concentration of the amino     acid sequence, compound or polypeptide to be reduced by 50%, in     vivo, for example due to degradation of the sequence or compound     and/or clearance or sequestration of the sequence or compound by     natural mechanisms. The in vivo half-life of an amino acid sequence,     compound or polypeptide of the invention can be determined in any     manner known per se, such as by pharmacokinetic analysis. Suitable     techniques will be clear to the person skilled in the art, and may     for example generally be as described in paragraph o) on page 57 of     WO 08/020079. As also mentioned in paragraph o) on page 57 of WO     08/020079, the half-life can be expressed using parameters such as     the t½-alpha, t½-beta and the area under the curve (AUC). Reference     is for example made to the Experimental Part below, as well as to     the standard handbooks, such as Kenneth, A et al: Chemical Stability     of Pharmaceuticals: A Handbook for Pharmacists and Peters et al,     Pharmacokinete analysis: A Practical Approach (1996). Reference is     also made to “Pharmacokinetics”, M Gibaldi & D Perron, published by     Marcel Dekker, 2nd Rev. edition (1982). The terms “increase in     half-life” or “increased half-life” as also as defined in     paragraph o) on page 57 of WO 08/020079 and in particular refer to     an increase in the t½-beta, either with or without an increase in     the t½-alpha and/or the AUC or both. -   q) In respect of a target or antigen, the term “interaction site” on     the target or antigen means a site, epitope, antigenic determinant,     part, domain or stretch of amino acid residues on the target or     antigen that is a site for binding to a ligand, receptor or other     binding partner, a catalytic site, a cleavage site, a site for     allosteric interaction, a site involved in multimerisation (such as     homomerization or heterodimerization) of the target or antigen; or     any other site, epitope, antigenic determinant, part, domain or     stretch of amino acid residues on the target or antigen that is     involved in a biological action or mechanism of the target or     antigen. More generally, an “interaction site” can be any site,     epitope, antigenic determinant, part, domain or stretch of amino     acid residues on the target or antigen to which an amino acid     sequence or polypeptide of the invention can bind such that the     target or antigen (and/or any pathway, interaction, signalling,     biological mechanism or biological effect in which the target or     antigen is involved) is modulated (as defined herein). -   r) An immunoglobulin single variable domain or polypeptide is said     to be “specific for” a first target or antigen compared to a second     target or antigen when is binds to the first antigen with an     affinity/avidity (as described above, and suitably expressed as a     K_(D) value, K_(A) value, K_(off) rate and/or K_(on) rate) that is     at least 10 times, such as at least 100 times, and preferably at     least 1000 times, and up to 10.000 times or more better than the     affinity with which said amino acid sequence or polypeptide binds to     the second target or polypeptide. For example, the first antigen may     bind to the target or antigen with a K_(D) value that is at least 10     times less, such as at least 100 times less, and preferably at least     1000 times less, such as 10.000 times less or even less than that,     than the K_(D) with which said amino acid sequence or polypeptide     binds to the second target or polypeptide. Preferably, when an     immunoglobulin single variable domain or polypeptide is “specific     for” a first target or antigen compared to a second target or     antigen, it is directed against (as defined herein) said first     target or antigen, but not directed against said second target or     antigen. -   s) The terms “cross-block”, “cross-blocked” and “cross-blocking” are     used interchangeably herein to mean the ability of an immunoglobulin     single variable domain or polypeptide to interfere with the binding     directly or indirectly through allosteric modulation of other     immunoglobulin single variable domains or polypeptides of the     invention to a given target. The extend to which an immunoglobulin     single variable domain or polypeptide of the invention is able to     interfere with the binding of another to target, and therefore     whether it can be said to cross-block according to the invention,     can be determined using competition binding assays. One particularly     suitable quantitative cross-blocking assay uses a FACS- or an     ELISA-based approach to measure competition between the labelled     (e.g. His tagged or radioactive labelled) immunoglobulin single     variable domain or polypeptide according to the invention and the     other binding agent in terms of their binding to the target. The     experimental part generally describes suitable FACS-, ELISA- or     radioligand-displacement-based assays for determining whether a     binding molecule cross-blocks or is capable of cross-blocking an     immunoglobulin single variable domain or polypeptide according to     the invention. It will be appreciated that the assay can be used     with any of the immunoglobulin single variable domains or other     binding agents described herein. Thus, in general, a cross-blocking     amino acid sequence or other binding agent according to the     invention is for example one which will bind to the target in the     above cross-blocking assay such that, during the assay and in the     presence of a second amino acid sequence or other binding agent of     the invention, the recorded displacement of the immunoglobulin     single variable domain or polypeptide according to the invention is     between 60% and 100% (e.g. in ELISA/radioligand based competition     assay) or between 80% to 100% (e.g. in FACS based competition assay)     of the maximum theoretical displacement (e.g. displacement by cold     (e.g. unlabeled) immunoglobulin single variable domain or     polypeptide that needs to be cross-blocked) by the to be tested     potentially cross-blocking agent that is present in an amount of     0.01 mM or less (cross-blocking agent may be another conventional     monoclonal antibody such as IgG, classic monovalent antibody     fragments (Fab, scFv)) and engineered variants (diabodies,     triabodies, minibodies, VHHs, dAbs, VHs, VLs). -   t) An amino acid sequence such as e.g. an immunoglobulin single     variable domain or polypeptide according to the invention is said to     be “cross-reactive” for two different antigens or antigenic     determinants (such as serum albumin from two different species of     mammal, such as human serum albumin and cyno serum albumin) if it is     specific for (as defined herein) both these different antigens or     antigenic determinants. -   u) As further described in paragraph q) on pages 58 and 59 of WO     08/020079 (incorporated herein by reference), the amino acid     residues of an immunoglobulin single variable domain are numbered     according to the general numbering for V_(H) domains given by Kabat     et al. (“Sequence of proteins of immunological interest”, US Public     Health Services, NIH Bethesda, Md., Publication No. 91), as applied     to V_(HH) domains from Camelids in the article of Riechmann and     Muyldermans, J. Immunol. Methods 2000 Jun. 23; 240 (1-2): 185-195     (see for example FIG. 2 of this publication), and accordingly FR1 of     an immunoglobulin single variable domain comprises the amino acid     residues at positions 1-30, CDR1 of an immunoglobulin single     variable domain comprises the amino acid residues at positions     31-35, FR2 of an immunoglobulin single variable domain comprises the     amino acids at positions 36-49, CDR2 of an immunoglobulin single     variable domain comprises the amino acid residues at positions     50-65, FR3 of an immunoglobulin single variable domain comprises the     amino acid residues at positions 66-94, CDR3 of an immunoglobulin     single variable domain comprises the amino acid residues at     positions 95-102, and FR4 of an immunoglobulin single variable     domain comprises the amino acid residues at positions 103-113. -   v) The Figures, Sequence Listing and the Experimental Part/Examples     are only given to further illustrate the invention and should not be     interpreted or construed as limiting the scope of the invention     and/or of the appended claims in any way, unless explicitly     indicated otherwise herein.

1. Polypeptides of the Invention and Uses Thereof

1.1. Anti-CXCR7 Building Blocks

The polypeptides of the present invention can generally be used to modulate, and in particular inhibit and/or prevent, binding of CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) to CXCL12 (and/or CXCL11) and in particular human CXCL12 (NM_000609) and/or in particular human CXCL11 (U66096), and thus to modulate, and in particular inhibit or prevent, the signalling that is mediated by CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) and/or CXCL12 (and/or CXCL11) and in particular human CXCL12 (NM_000609) and/or in particular human CXCL11 (U66096), to modulate the biological pathways in which CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) and/or CXCL12 (and/or CXCL11) and in particular human CXCL12 (NM_000609) and/or in particular human CXCL11 (U66096) are involved, and/or to modulate the biological mechanisms, responses and effects associated with such signalling or these pathways.

As such, the polypeptides and compositions of the present invention can be used for the diagnosis, prevention and treatment of diseases and disorders of the present invention (herein also “diseases and disorders of the present invention”) and include, but are not limited to cancer, e.g., carcinomas, gliomas, mesotheliomas, melanomas, lymphomas, leukemias, adenocarcinomas, breast cancer, ovarian cancer, cervical cancer, glioblastoma, leukemia, lymphoma, prostate cancer, and Burkitt's lymphoma, head and neck cancer, colon cancer, colorectal cancer, non-small cell lung cancer, small cell lung cancer, cancer of the esophagus, stomach cancer, pancreatic cancer, hepatobiliary cancer, cancer of the gallbladder, cancer of the small intestine, rectal cancer, kidney cancer, bladder cancer, prostate cancer, penile cancer, urethral cancer, testicular cancer, cervical cancer, vaginal cancer, uterine cancer, ovarian cancer, thyroid cancer, parathyroid cancer, adrenal cancer, pancreatic endocrine cancer, carcinoid cancer, bone cancer, skin cancer, retinoblastomas, Hodgkin's lymphoma, non-Hodgkin's lymphoma, Kaposi's sarcoma, multicentric Castleman's disease or AIDS-associated primary effusion lymphoma, neuroectodermal tumors, rhabdomyosarcoma (see, Cancer, Principles and practice (DeVita, V. T. et al. eds 1997) for additional cancers); as well as brain and neuronal dysfunction, such as Alzheimer's disease and multiple sclerosis; kidney dysfunction, renal allograft rejection; nasal polyposis; rheumatoid arthritis; cardiac allograft rejection; cardiac dysfunction; atherosclerosis; asthma; glomerulonephritis; contact dermatitis; inflammatory bowel disease; colitis, psoriasis; reperfusion injury; as well as other disorders and diseases described herein. In particular, the polypeptides and compositions of the present invention can be used for the diagnosis, prevention and treatment of diseases involving CXCR7 mediated metastasis, chemotaxis, cell adhesion, trans endothelial migration, cell proliferation and/or survival.

Generally, said “diseases and disorders of the present invention” can be defined as diseases and disorders that can be diagnosed, prevented and/or treated, respectively, by suitably administering to a subject in need thereof (i.e. having the disease or disorder or at least one symptom thereof and/or at risk of attracting or developing the disease or disorder) of either a polypeptide or composition of the invention (and in particular, of a pharmaceutically active amount thereof) and/or of a known active principle active against CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) or a biological pathway or mechanism in which CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) is involved (and in particular, of a pharmaceutically active amount thereof).

In particular, the polypeptides of the present invention can be used for the diagnosis, prevention and treatment of diseases and disorders of the present invention which are characterized by excessive and/or unwanted CXCL12 and in particular human CXCL12 signalling mediated by CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) or by the pathway(s) in which CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) is involved (e.g. CXCL11/I-TAC-CXCR7 axis). Examples of such diseases and disorders of the present invention will again be clear to the skilled person based on the disclosure herein.

Thus, without being limited thereto, the immunoglobulin single variable domains and polypeptides of the invention can for example be used to diagnose, prevent and/or to treat all diseases and disorders that are currently being diagnosed, prevented or treated with active principles that can modulate CXCR7 and in particular human CXCR7 (SEQ ID NO: 1)-mediated signalling, such as those mentioned in the prior art cited above. It is also envisaged that the polypeptides of the invention can be used to diagnose, prevent and/or to treat all diseases and disorders for which treatment with such active principles is currently being developed, has been proposed, or will be proposed or developed in future. In addition, it is envisaged that, because of their favourable properties as further described herein, the polypeptides of the present invention may be used for the diagnosis, prevention and treatment of other diseases and disorders than those for which these known active principles are being used or will be proposed or developed; and/or that the polypeptides of the present invention may provide new methods and regimens for treating the diseases and disorders described herein.

Other applications and uses of the immunoglobulin single variable domains and polypeptides of the invention will become clear to the skilled person from the further disclosure herein.

Generally, it is an object of the invention to provide pharmacologically active agents, as well as compositions comprising the same, that can be used in the diagnosis, prevention and/or treatment of diseases and/or disorders of the invention; and to provide methods for the diagnosis, prevention and/or treatment of such diseases and disorders that involve the administration and/or use of such agents and compositions.

In particular, it is an object of the invention to provide such pharmacologically active agents, compositions and/or methods that have certain advantages compared to the agents, compositions and/or methods that are currently used and/or known in the art. These advantages will become clear from the further description below.

More in particular, it is an object of the invention to provide therapeutic proteins that can be used as pharmacologically active agents, as well as compositions comprising the same, for the diagnosis, prevention and/or treatment of diseases and/or disorders of the invention and of the further diseases and disorders mentioned herein; and to provide methods for the diagnosis, prevention and/or treatment of such diseases and disorders that involve the administration and/or the use of such therapeutic proteins and compositions.

Accordingly, it is a specific object of the present invention to provide immunoglobulin single variable domains that are directed against CXCR7, in particular against CXCR7 from a warm-blooded animal, more in particular against CXCR7 from a mammal such as e.g. mouse, and especially against human CXCR7 (SEQ ID NO: 1); and to provide proteins and polypeptides comprising or essentially consisting of at least one such immunoglobulin single variable domain.

In particular, it is a specific object of the present invention to provide such immunoglobulin single variable domains and such proteins and/or polypeptides that are suitable for prophylactic, therapeutic and/or diagnostic use in a warm-blooded animal, and in particular in a mammal, and more in particular in a human being.

More in particular, it is a specific object of the present invention to provide such immunoglobulin single variable domains and such proteins and/or polypeptides that can be used for the prevention, treatment, alleviation and/or diagnosis of one or more diseases, disorders or conditions associated with CXCR7 and/or mediated by CXCR7 (such as the diseases, disorders and conditions mentioned herein) in a warm-blooded animal, in particular in a mammal, and more in particular in a human being.

It is also a specific object of the invention to provide such immunoglobulin single variable domains and such proteins and/or polypeptides that can be used in the preparation of pharmaceutical or veterinary compositions for the prevention and/or treatment of one or more diseases, disorders or conditions associated with and/or mediated by CXCR7 (such as the diseases, disorders and conditions mentioned herein) in a warm-blooded animal, in particular in a mammal, and more in particular in a human being.

In the invention, generally, these objects are achieved by the use of the immunoglobulin single variable domains, proteins, polypeptides and compositions that are described herein.

In general, the invention provides immunoglobulin single variable domains that are directed against (as defined herein) and/or can specifically bind (as defined herein) to CXCR7 and in particular human CXCR7 (SEQ ID NO: 1); as well as compounds and constructs, and in particular proteins and polypeptides, that comprise at least one such amino acid sequence.

More in particular, the invention provides immunoglobulin single variable domains and polypeptides that can bind to CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) with an affinity (suitably measured and/or expressed as a K_(D)-value (actual or apparent), a K_(A)-value (actual or apparent), a k_(on)-rate and/or a k_(off)-rate, or alternatively as an IC₅₀ value, as further described herein) that is as defined herein; as well as compounds and constructs, and in particular proteins and polypeptides, that comprise at least one such amino acid sequence.

In particular aspect, the immunoglobulin single variable domains and/or polypeptides of the invention are such that they:

-   -   bind to human CXCR7 (SEQ ID NO:1) with an EC50 of 100 nM or         lower, more preferably of 50 nM or lower, even more preferably         of 20 nM or lower, most preferably of 10 nM or lower in a         binding FACS assay as e.g. described in the experimental part         (see example 8), and wherein the polypeptides comprise only one         human CXCR7 binding immunoglobulin single variable domain unit;         and/or such that they:     -   fully displace human CXCL12 (SDF-1) from human CXCR7 (SEQ ID         NO: 1) at an average Ki value of 100 nM or less, more preferably         at an average Ki value of 20 nM or less, even more preferably at         an average Ki value of 10 nM or less in an assay as e.g.         described in the experimental part (examples 9 and 10), and         wherein the polypeptides comprise only one human CXCR7 binding         immunoglobulin single variable domain unit, and wherein full         displacement means an average CXCL12 displacement of about 60%         to 80% and more (e.g. when measured according to the ligand         displacement assay of example 9) or wherein full displacement         means an average CXCL12 displacement of about 80% to 100% and         more (when measured according to the FACS based competition         assay of example 10);         and/or such that they:     -   fully displace human CXCL11 (I-TAC) from human CXCR7 (SEQ ID         NO: 1) at an average Ki value of 1000 nM or less, more         preferably at an average Ki value 500 nM or less, even more         preferably at an average Ki value 100 nM or less, even more         preferably at an average Ki value of 20 nM or less, even more         preferably at an average Ki value of 10 nM or less in an assay         as e.g. described in the experimental part (examples 9 and 10),         and wherein the polypeptides comprise only one human CXCR7         binding immunoglobulin single variable domain unit, and wherein         full displacement means an average CXCL11 displacement of about         60% to 80% and more (e.g. when measured according to the ligand         displacement assay of example 9) or wherein full displacement         means an average CXCL12 displacement of about 80% to 100% and         more (when measured according to the FACS based competition         assay of example 10) and/or such that they:     -   partially displace human CXCL12 (SDF-1) from human CXCR7 (SEQ ID         NO: 1) at an average Ki value of 100 nM or less, more preferably         at an average Ki value of 20 nM or less, even more preferably at         an average Ki value of 10 nM or less in an assay as e.g.         described in the experimental part (examples 9 and 10), and         wherein the polypeptides comprise only one human CXCR7 binding         immunoglobulin single variable domain unit, and wherein partial         displacement means an average CXCL12 displacement of about 40%         to 60% (e.g. when measured according to the ligand displacement         assay of example 9) or wherein partial displacement means an         average CXCL12 displacement of about 50% to 80% (when measured         according to the FACS based competition assay of example 10);         and/or such that they:

partially displace human CXCL11 (I-TAC) from human CXCR7 (SEQ ID NO: 1) at an average Ki value of 1000 nM or less, more preferably at an average Ki value 500 nM or less, even more preferably at an average Ki value 100 nM or less, even more preferably at an average Ki value of 20 nM or less, even more preferably at an average Ki value of 10 nM or less in an assay as e.g. described in the experimental part (examples 9 and 10), and wherein the polypeptides comprise only one human CXCR7 binding immunoglobulin single variable domain unit, and wherein partial displacement means an average CXCL11 displacement of about 40% to 60% (e.g. when measured according to the ligand displacement assay of example 9) or wherein partial displacement means an average CXCL12 displacement of about 50% to 80% (when measured according to the FACS based competition assay of example 10). Some preferred technical values for binding, displacing, migration or other in vivo and/or in vitro potency of the immunoglobulin single variable domains or polypeptides of the invention to CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) will become clear from the further description and examples herein.

For binding to CXCR7 and in particular human CXCR7 (SEQ ID NO: 1), an amino acid sequence of the invention will usually contain within its amino acid sequence one or more amino acid residues or one or more stretches of amino acid residues (i.e. with each “stretch” comprising two or amino acid residues that are adjacent to each other or in close proximity to each other, i.e. in the primary or tertiary structure of the amino acid sequence) via which the amino acid sequence of the invention can bind to CXCR7 and in particular human CXCR7 (SEQ ID NO: 1), which amino acid residues or stretches of amino acid residues thus form the “site” for binding to CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) (also referred to herein as the “antigen binding site”).

The immunoglobulin single variable domains provided by the invention are preferably in essentially isolated form (as defined herein), or form part of a protein or polypeptide of the invention (as defined herein), which may comprise or essentially consist of one or more immunoglobulin single variable domains of the invention and which may optionally further comprise one or more further immunoglobulin single variable domains (all optionally linked via one or more suitable linkers), and/or one or more further binding domains, binding units, amino acid sequences or other (functional) groups or moieties, that preferably also confer one or more desired properties to the constructs (some non-limiting examples of the same will become clear from the further description herein). Again, such further binding domains, binding units, amino acid sequences or other (functional) groups or moieties may for example be one or more other immunoglobulin single variable domains, such as one or more (single) domain antibodies, dAb's or Nanobodies (e.g. a V_(HH), humanized V_(HH) or camelized V_(H), such as a camelised human V_(H)), so as to provide a “bispecific” protein or polypeptide of the invention (i.e. a polypeptide of the invention that contains at least one—such as one or two—immunoglobulin single variable domain that is directed against CXCR7 and at least one—such as one or two—immunoglobulin single variable domain that is directed against another target).

For example, according to a specific but non-limiting aspect, the constructs, proteins or polypeptides of the invention may have been provided with an increased half-life, for example by functionalisation and/or by including in the construct a moiety or binding unit that increases the half-life of the construct. Examples of such functionalisation, moieties or binding units will be clear to the skilled person and may for example include pegylation, fusion to serum albumin, or fusion to a peptide or binding unit that can bind to a serum protein such as serum albumin

In the latter constructs (i.e. fusion constructs comprising at least one—such as one or two—amino acid sequence of the invention and at least one—such as one or two—peptide or binding unit that can bind to a serum protein such as serum albumin), the serum-albumin binding peptide or binding domain may be any suitable serum-albumin binding peptide or binding domain capable of increasing the half-life of the construct (compared to the same construct without the serum-albumin binding peptide or binding domain), and may in particular be serum albumin binding peptides as described in WO 2008/068280 by applicant (and in particular WO 2009/127691 and the non-prepublished U.S. application 61/301,819, both by applicant), or a serum-albumin binding immunoglobulin single variable domain (such as a serum-albumin binding Nanobody; for example Alb-1 or a humanized version of Alb-1 such as Alb-8, for which reference is for example made to WO 06/122787).

With respect to half-life, it should be noted that in the invention, and by using the various half-life extending techniques described herein (for example, by suitably choosing a serum-albumin binding peptide according to WO 2008/068280, WO 2009/127691 and/or the non-prepublished U.S. application 61/301,819), the half-life of a construct or polypeptide of the invention can (and preferably is) suitably “tailored” for the intended (therapeutic and/or diagnostic) application and/or to obtain the best balance between the desired therapeutic and/or pharmacological effect and possible undesired side-effects.

Thus, for example, and without limitation, a preferred aspect of the invention provides a “bispecific” polypeptide consisting essentially of one immunoglobulin single variable domain directed against human CXCR7 (or, alternatively, of two immunoglobulin single variable domains directed against human CXCR7, which may be the same or different, i.e. so as to provide—when they are the same or different—a “bivalent” polypeptide of the invention, or—when they are different—“biparatopic” polypeptide of the invention) and one immunoglobulin single variable domain directed against human serum albumin linked by a peptide linker (as defined herein), so as to provide a bispecific polypeptide of the invention, respectively, all as described herein. Such a protein or polypeptide may also be in essentially isolated form (as defined herein).

In another specific, but non-limiting aspect, an amino acid sequence (such as a Nanobody) of the invention or a polypeptide of the invention (such as a bivalent, biparatopic or bispecific polypeptide of the invention) may be suitably linked (again, chemically or via one or more suitable linkers or spacers) to a toxin or to a (cyto)toxic residue, moiety or payload. Examples of suitable (cyto)toxic moieties, compounds, payloads or residues which can be linked to amino acids sequences or polypeptides of the invention to provide—for example—a cytotoxic compound (i.e. an antibody-drug conjugate or “ADC” based upon an amino acid sequence or polypeptide of the invention) will be clear to the skilled person. Reference is for example made to the review by Ducry and Stump, Bioconjugate Chem., 2010, 21 (1), pp 5-13. Such cytotoxic amino acid sequences or polypeptides of the invention may in particular be useful/suitable for those applications in which it is intended to kill a cell that expresses the target against which the amino acid sequences or polypeptides of the invention are directed (e.g. in the treatment of cancer), or to reduce or slow the growth and/or proliferation such a cell. Usually, but without limitation, (cyto)toxic polypeptides of the invention will either not be half-life extended or will have only a limited and/or tightly controlled half-life extension.

In another aspect, at least one amino acid sequence of the invention (i.e. immunoglobulin single variable domain against CXCR7) may be suitably linked to at least one immunoglobulin single variable domain that is directed against CXCR4, so as to provide a bispecific polypeptide of the invention that is directed against both CXCR7 and CXCR4.

For example, in this aspect, at least one—such as one or two—amino acid sequences of the invention may be suitably linked to at least one—such as one or two—immunoglobulin single variable domains against CXCR4.

Some preferred but non-limiting examples of immunoglobulin single variable domains against CXCR4 that can be used in such constructs are (or may be suitably chosen from)

-   -   the immunoglobulin single variable domains (and in particular         one of the Nanobodies) against CXCR4 from the international         application WO 09/138519 by Ablynx N.V. (for example and without         limitation, 238D2/SEQ ID NO: 238 and 238D4/SEQ ID NO: 239 in         Table B-1.1 of WO 09/138519); and/or     -   the sequence-optimized/improved variants of the amino acid         sequences 238D2 and 238D4 described in the non-prepublished U.S.         application 61/358,495 by Ablynx N.V. filed on Jun. 25, 2010;         and/or     -   the immunoglobulin single variable domains that are capable of         binding to the same epitope as 238D2 and/or 238D4 as described         in the PCT application PCT/EP210/064766 by Ablynx N.V. filed on         Oct. 4, 2010; and/or     -   the 10E9-type sequences, 281E10-type sequences, 10E12-type         sequences, 10A10-type sequences, 10G10-type sequences, 14A2-type         sequences, 15A1-type sequences, 15H3-type sequences and/or         283B6-type sequences described on pages 7-13 of the PCT         application PCT/EP2011/050156 by Ablynx N.V. filed on Jan. 7,         2011; and/or     -   the 10E9-type sequences, 281E10-type sequences, 10E12-type         sequences, 10A10-type sequences, 10G10-type sequences, 14A2-type         sequences, 15A1-type sequences, 15H3-type sequences and/or         283B6-type sequences described on pages 15-47 of the PCT         application PCT/EP2011/050156 by Ablynx N.V. filed on Jan. 7,         2011.

The above anti-CXCR7/CXCR4 bispecific constructs (as well as other bispecific constructs comprising at least one amino acid sequence of the invention) may again be suitably half-life extended (i.e. by pegylation, fusion to serum albumin, or fusion to a peptide or binding unit that can bind to a serum protein such as serum albumin, as further described herein), and thus may for example further comprise a serum-albumin binding peptide or binding domain (such as those described herein), optionally linked via one or more suitable spacers or linkers.

Thus, one specific but non-limiting aspect of the invention is a polypeptide that comprises one or two (and preferably one) immunoglobulin single variable domains (as defined herein, and preferably one or two Nanobodies) against CXCR7, one or two (and preferably one) immunoglobulin single variable domains (as defined herein, and preferably one or two Nanobodies) against CXCR4, and a peptide or immunoglobulin single variable domain against (human) serum albumin, optionally suitably linked via one or more spacers or linkers.

The above anti-CXCR7/CXCR4 bispecific constructs (as well as other bispecific constructs comprising at least one amino acid sequence of the invention) may also be suitably linked (again, chemically or via one or more suitable linkers or spacers) to a toxin or to a (cyto)toxic residue, moiety or payload (as further described herein). Again, such (cyto)toxic bispecific polypeptides of the invention will either not be half-life extended or will have only a limited and/or tightly controlled half-life extension.

The invention in its broadest sense also comprises derivatives of the amino acid sequences (e.g., Nanobodies) of the invention and of the polypeptides of the invention. Such derivatives can generally be obtained by modification, and in particular by chemical and/or biological (e.g., enzymatical) modification, of the amino acid sequences (e.g. Nanobodies) of the invention and polypeptides of the invention and/or of one or more of the amino acid residues that form the Nanobodies of the invention.

Examples of such modifications, as well as examples of amino acid residues within the amino acid sequences (e.g. Nanobodies) of the invention and polypeptides that can be modified in such a manner (i.e. either on the protein backbone but preferably on a side chain), methods and techniques that can be used to introduce such modifications and the potential uses and advantages of such modifications will be clear to the skilled person.

For example, such a modification may involve the introduction (e.g. by covalent linking or in an other suitable manner) of one or more functional groups, residues or moieties into or onto the amino acid sequences (e.g. Nanobodies) of the invention and polypeptides of the invention, and in particular of one or more functional groups, residues or moieties that confer one or more desired properties or functionalities to the Nanobody of the invention. Example of such functional groups will be clear to the skilled person.

For example, such modification may comprise the introduction (e.g. by covalent binding or in any other suitable manner) of one or more functional groups that increase the half-life, the solubility and/or the absorption of the Nanobody of the invention, that reduce the immunogenicity and/or the toxicity of the Nanobody of the invention, that eliminate or attenuate any undesirable side effects of the Nanobody of the invention, and/or that confer other advantageous properties to and/or reduce the undesired properties of the Nanobodies and/or polypeptides of the invention; or any combination of two or more of the foregoing. Examples of such functional groups and of techniques for introducing them will be clear to the skilled person, and can generally comprise all functional groups and techniques mentioned in the general background art cited hereinabove as well as the functional groups and techniques known per se for the modification of pharmaceutical proteins, and in particular for the modification of antibodies or antibody fragments (including ScFv's and single domain antibodies), for which reference is for example made to Remington's Pharmaceutical Sciences, 16th ed., Mack Publishing Co., Easton, Pa. (1980). Such functional groups may for example be linked directly (for example covalently) to a Nanobody of the invention, or optionally via a suitable linker or spacer, as will again be clear to the skilled person.

One of the most widely used techniques for increasing the half-life and/or reducing the immunogenicity of pharmaceutical proteins comprises attachment of a suitable pharmacologically acceptable polymer, such as poly(ethyleneglycol) (PEG) or derivatives thereof (such as methoxypoly(ethyleneglycol) or mPEG). Generally, any suitable form of pegylation can be used, such as the pegylation used in the art for antibodies and antibody fragments (including but not limited to (single) domain antibodies and ScFv's); reference is made to for example Chapman, Nat. Biotechnol., 54, 531-545 (2002); by Veronese and Harris, Adv. Drug Deliv. Rev. 54, 453-456 (2003), by Harris and Chess, Nat. Rev. Drug. Discov., 2, (2003) and in WO 04/060965. Various reagents for pegylation of proteins are also commercially available, for example from Nektar Therapeutics, USA.

Preferably, site-directed pegylation is used, in particular via a cysteine-residue (see for example Yang et al., Protein Engineering, 16, 10, 761-770 (2003). For example, for this purpose, PEG may be attached to a cysteine residue that naturally occurs in a Nanobody of the invention, a Nanobody of the invention may be modified so as to suitably introduce one or more cysteine residues for attachment of PEG, or an amino acid sequence comprising one or more cysteine residues for attachment of PEG may be fused to the N- and/or C-terminus of a Nanobody of the invention, all using techniques of protein engineering known per se to the skilled person.

Preferably, for the Nanobodies and proteins of the invention, a PEG is used with a molecular weight of more than 5000, such as more than 10,000 and less than 200,000, such as less than 100,000; for example in the range of 20,000-80,000.

Another, usually less preferred modification comprises N-linked or O-linked glycosylation, usually as part of co-translational and/or post-translational modification, depending on the host cell used for expressing the Nanobody or polypeptide of the invention.

Yet another modification may comprise the introduction of one or more detectable labels or other signal-generating groups or moieties, depending on the intended use of the labelled Nanobody. Suitable labels and techniques for attaching, using and detecting them will be clear to the skilled person, and for example include, but are not limited to, the fluorescent labels, phosphorescent labels, chemiluminescent labels, bioluminescent labels, radio-isotopes, metals, metal chelates, metallic cations, chromophores and enzymes, such as those mentioned on page 109 of WO 08/020079. Other suitable labels will be clear to the skilled person, and for example include moieties that can be detected using NMR or ESR spectroscopy.

Such labelled Nanobodies and polypeptides of the invention may for example be used for in vitro, in vivo or in situ assays (including immunoassays known per se such as ELISA, RIA, EIA and other “sandwich assays”, etc.) as well as in vivo diagnostic and imaging purposes, depending on the choice of the specific label.

As will be clear to the skilled person, another modification may involve the introduction of a chelating group, for example to chelate one of the metals or metallic cations referred to above. Suitable chelating groups for example include, without limitation, diethyl-enetriaminepentaacetic acid (DTPA) or ethylenediaminetetraacetic acid (EDTA).

Yet another modification may comprise the introduction of a functional group that is one part of a specific binding pair, such as the biotin-(strept)avidin binding pair. Such a functional group may be used to link the Nanobody of the invention to another protein, polypeptide or chemical compound that is bound to the other half of the binding pair, i.e. through formation of the binding pair. For example, a Nanobody of the invention may be conjugated to biotin, and linked to another protein, polypeptide, compound or carrier conjugated to avidin or streptavidin. For example, such a conjugated Nanobody may be used as a reporter, for example in a diagnostic system where a detectable signal-producing agent is conjugated to avidin or streptavidin. Such binding pairs may for example also be used to bind the Nanobody of the invention to a carrier, including carriers suitable for pharmaceutical purposes. One non-limiting example are the liposomal formulations described by Cao and Suresh, Journal of Drug Targeting, 8, 4, 257 (2000). Such binding pairs may also be used to link a therapeutically active agent to the Nanobody of the invention.

Other potential chemical and enzymatical modifications will be clear to the skilled person. Such modifications may also be introduced for research purposes (e.g. to study function-activity relationships). Reference is for example made to Lundblad and Bradshaw, Biotechnol. Appl. Biochem., 26, 143-151 (1997).

The immunoglobulin single variable domains and polypeptides of the invention as such preferably essentially consist of a single amino acid chain that is not linked via disulphide bridges to any other amino acid sequence or chain (but that may or may not contain one or more intramolecular disulphide bridges. For example, it is known that agent of the invention—as described herein—may sometimes contain a disulphide bridge between CDR3 and CDR1 or FR2). However, it should be noted that one or more immunoglobulin single variable domains of the invention may be linked to each other and/or to other immunoglobulin single variable domains (e.g. via disulphide bridges) to provide peptide constructs that may also be useful in the invention (for example Fab′ fragments, F(ab′)₂ fragments, ScFv constructs, “diabodies” and other multispecific constructs. Reference is for example made to the review by Holliger and Hudson, Nat Biotechnol. 2005 September; 23(9):1126-36).

Generally, when an amino acid sequence of the invention (or a compound, construct or polypeptide comprising the same) is intended for administration to a subject (for example for therapeutic and/or diagnostic purposes as described herein), it is preferably either an amino acid sequence that does not occur naturally in said subject; or, when it does occur naturally in said subject, is in essentially isolated form (as defined herein).

It will also be clear to the skilled person that for pharmaceutical use, the immunoglobulin single variable domains of the invention (as well as compounds, constructs and polypeptides comprising the same) are preferably directed against human CXCR7 and in particular human CXCR7 (SEQ ID NO: 1); whereas for veterinary purposes, the immunoglobulin single variable domains and polypeptides of the invention are preferably directed against CXCR7 from the species to be treated, or at at least cross-reactive with CXCR7 from the species to be treated.

Furthermore, an amino acid sequence of the invention may optionally, and in addition to the at least one binding site for binding against CXCR7 and in particular human CXCR7 (SEQ ID NO: 1), contain one or more further binding sites for binding against other antigens, proteins or targets.

The efficacy of the immunoglobulin single variable domains and polypeptides of the invention, and of compositions comprising the same, can be tested using any suitable in vitro assay, cell-based assay, in vivo assay and/or animal model known per se, or any combination thereof, depending on the specific disease or disorder involved. Suitable assays and animal models will be clear to the skilled person, and for example include ligand displacement assays (Burns et al, J Exp Med. 2006 4; 203(9):2201-13), beta arrestin recruitment assays (Zabel et al J Immunol. 2009 1; 183(5):3204-11), dimerization assays (Luker et al, FASEB J 2009.; 23(3):823-34), signaling assays (Wang et al, J Immunol. 2009 Sep. 1; 183(5):3204-11) proliferation assays (Wang et al, J Immunol. 2009 Sep. 1; 183(5):3204-11; Odemis et al., J Cell Sign. 2010 Apr. 1; 123(Pt 7): 1081-8), survival assays (Burns et al, J Exp Med. 2006 4; 203(9):2201-13), cell adhesion assays (Burns et al, J Exp Med. 2006 4; 203(9):2201-13) and transendothelial migration assays (Mazzinghi et al, J Exp Med. 2008 Feb. 18; 205(2):479-90), endothelial cell sprouting assays (Wang et al, J Immunol. 2009 Sep. 1; 183(5):3204-11), myogenic differentiation (Melchionna et al., Muscle Nerve, 2010 Feb. 11) and in vivo xenograft models (Burns et al, J Exp Med. 2006 4; 203(9):2201-13), collagen induced arthritis models (Hegen et al, Ann Rheum Dis. 2008 November; 67(11):1505-15) and experimental autoimmune encephalomyelitis models (Wekerle, Ann Rheum Dis. 2008 December; 67 Suppl 3:iii56-60) as well as the assays and animal models used in the experimental part below and in the prior art cited herein.

Also, according to the invention, immunoglobulin single variable domains and polypeptides that are directed against CXCR7 from a first species of warm-blooded animal may or may not show cross-reactivity with CXCR7 from one or more other species of warm-blooded animal. For example, immunoglobulin single variable domains and polypeptides directed against human CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) may or may not show cross reactivity with CXCR7 from one or more other species of primates (such as, without limitation, monkeys from the genus Macaca (such as, and in particular, cynomolgus monkeys (Macaca fascicularis) and/or rhesus monkeys (Macaca mulatta)) and baboon (Papio ursinus)) and/or with CXCR7 from one or more species of animals that are often used in animal models for diseases (for example mouse, rat, rabbit, pig or dog), and in particular in animal models for diseases and disorders associated with CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) (such as the species and animal models mentioned herein). In this respect, it will be clear to the skilled person that such cross-reactivity, when present, may have advantages from a drug development point of view, since it allows the immunoglobulin single variable domains and polypeptides against human CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) to be tested in such disease models.

More generally, immunoglobulin single variable domains and polypeptides of the invention that are cross-reactive with CXCR7 from multiple species of mammal will usually be advantageous for use in veterinary applications, since it will allow the same amino acid sequence or polypeptide to be used across multiple species. Thus, it is also encompassed within the scope of the invention that immunoglobulin single variable domains and polypeptides directed against CXCR7 from one species of animal (such as immunoglobulin single variable domains and polypeptides against human CXCR7 (SEQ ID NO: 1)) can be used in the treatment of another species of animal, as long as the use of the immunoglobulin single variable domains and/or polypeptides provide the desired effects in the species to be treated.

The present invention is in its broadest sense also not particularly limited to or defined by a specific antigenic determinant, epitope, part, domain, subunit or confirmation (where applicable) of CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) against which the immunoglobulin single variable domains and polypeptides of the invention are directed. For example, the immunoglobulin single variable domains and polypeptides may or may not be directed against the CXCL11/CXCL12 interaction site and/or CXCR7/CXCR7 homodimerization site and/or CXCR4/CXCR7 heterodimerization site (or heterodimerization of CXCR7 to other chemokine receptor such as e.g. CXCR3), and are as further defined herein.

As further described herein, a polypeptide of the invention may contain (although not preferred) two or more immunoglobulin single variable domains of the invention that are directed against CXCR7 and in particular human CXCR7 (SEQ ID NO: 1). Generally, such polypeptides will bind to CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) with increased avidity compared to a single amino acid sequence of the invention. Such a polypeptide may for example comprise two immunoglobulin single variable domains of the invention that are directed against the same antigenic determinant, epitope, part, domain, subunit or confirmation (where applicable) of CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) (which may or may not be an interaction site); or comprise at least one “first” amino acid sequence of the invention that is directed against a first same antigenic determinant, epitope, part, domain, subunit or confirmation (where applicable) of CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) (which may or may not be an interaction site); and at least one “second” amino acid sequence of the invention that is directed against a second antigenic determinant, epitope, part, domain, subunit or confirmation (where applicable) different from the first (and which again may or may not be an interaction site). Preferably, in such “biparatopic” polypeptides of the invention, at least one amino acid sequence of the invention is directed against an interaction site (as defined herein), although the invention in its broadest sense is not limited thereto. E.g. polypeptides of the invention may be formatted e.g. in a biparatopic way such as to combine monovalent building blocks directed against different epitopes as characterized in the experimental part (see examples 9 to 12).

Also, when the target is part of a binding pair (for example, a receptor-ligand binding pair), the immunoglobulin single variable domains and polypeptides may be such that they compete with the cognate binding partners, e.g. CXCL11 (also referred to as I-TAC) and/or CXCL12 (also referred to as SDF-1), for binding to CXCR7, and/or such that they (fully or partially) neutralize binding of the binding partner to the target.

It is also expected that the immunoglobulin single variable domains and polypeptides of the invention will generally bind to all naturally occurring or synthetic analogs, variants, mutants, alleles, parts and fragments of CXCR7 and in particular human CXCR7 (SEQ ID NO: 1); or at least to those analogs, variants, mutants, alleles, parts and fragments of CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) that contain one or more antigenic determinants or epitopes that are essentially the same as the antigenic determinant(s) or epitope(s) to which the immunoglobulin single variable domains and polypeptides of the invention bind to CXCR7 and in particular to human CXCR7 (SEQ ID NO: 1). Again, in such a case, the immunoglobulin single variable domains and polypeptides of the invention may bind to such analogs, variants, mutants, alleles, parts and fragments with an affinity and/or specificity that are the same as, or that are different from (i.e. higher than or lower than), the affinity and specificity with which the immunoglobulin single variable domains of the invention bind to (wild-type) CXCR7.

As CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) exists in a monomeric form and in one or more multimeric forms, e.g. in homodimeric as well in heterodimeric form with CXCR4, e.g. human CXCR4 (R M Maksym et al., supra; K E Luker et al. supra), it is within the scope of the invention that the immunoglobulin single variable domains and polypeptides of the invention i) only bind to CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) in monomeric form, ii) only bind to CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) in multimeric/dimeric (homo- and/or heterodimeric) form, or iii) bind to both the monomeric and the multimeric form. In a preferred aspect of the invention, the polypeptides of the invention prevent formation of homodimeric human CXCR7 complexes and/or heterodimeric human CXCR4/CXCR7 complexes. In another preferred aspect of the invention, the polypeptides of the invention do not induce (even at higher concentration such as 10 nM or less, 50 nM or less, 100 nM or less, or 500 nM or less) formation of homodimeric human CXCR7 complexes and/or heterodimeric human CXCR4/CXCR7 complexes. Again, in such a case, the polypeptides of the invention may bind to the monomeric form with an affinity and/or specificity that are the same as, or that are different from (i.e. higher than or lower than), the affinity and specificity with which the immunoglobulin single variable domains of the invention bind to the multimeric form.

Also, when CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) can associate with other proteins or polypeptides to form protein complexes (e.g. with CXCL12/SDF-1 or CXCL11/I-TAC), it is within the scope of the invention that the immunoglobulin single variable domains and polypeptides of the invention bind to CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) in its non-associated state (and e.g. prevent the ligand binding), bind to CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) in its associated state, or bind to both (preferably to the non-associated state). In all these cases, the immunoglobulin single variable domains and polypeptides of the invention may bind to such associated protein complexes with an affinity and/or specificity that may be the same as or different from (i.e. higher than or lower than) the affinity and/or specificity with which the immunoglobulin single variable domains and polypeptides of the invention bind to CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) in its non-associated state.

Also, as will be clear to the skilled person, proteins or polypeptides that contain two or more immunoglobulin single variable domains directed against CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) may bind with higher avidity to CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) than the corresponding monomeric amino acid sequence(s). For example, and without limitation, proteins or polypeptides that contain two or more immunoglobulin single variable domains directed against different epitopes of CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) may (and usually will) bind with higher avidity than each of the different monomers, and proteins or polypeptides that contain two or more immunoglobulin single variable domains directed against CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) may (and usually will) bind also with higher avidity to a multimer (e.g. homodimer, heterodimer with CXCR4) of CXCR7 and in particular to a multimer (e.g. homodimer, heterodimer with human CXCR4) of human CXCR7 (SEQ ID NO: 1).

Generally, immunoglobulin single variable domains and polypeptides of the invention will at least bind to those forms of CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) (including monomeric, multimeric, associated and different conformational forms) that are the most relevant from a biological and/or therapeutic point of view, as will be clear to the skilled person.

It is also within the scope of the invention to use parts, fragments, analogs, mutants, variants, alleles and/or derivatives of the immunoglobulin single variable domains and polypeptides of the invention, and/or to use proteins or polypeptides comprising or essentially consisting of one or more of such parts, fragments, analogs, mutants, variants, alleles and/or derivatives, as long as these are suitable for the uses envisaged herein. Such parts, fragments, analogs, mutants, variants, alleles and/or derivatives will usually contain (at least part of) a functional antigen-binding site for binding against CXCR7 and in particular human CXCR7 (SEQ ID NO: 1); and more preferably will be capable of specific binding to CXCR7 and in particular human CXCR7 (SEQ ID NO: 1), and even more preferably capable of binding to CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) with an EC50 value, average Ki, IC₅₀ value concerning binding, migration, displacing and/or proliferation blocking and/or other measures for potency, as further described herein, e.g. in the experimental part) that is as defined herein and such parts, fragments, analogs, mutants, variants, alleles and/or derivatives may be more potent, more stable, more soluble and may have the same epitope. Some non-limiting examples of such parts, fragments, analogs, mutants, variants, alleles, derivatives, proteins and/or polypeptides will become clear from the further description herein. Additional fragments or polypeptides of the invention may also be provided by suitably combining (i.e. by linking or genetic fusion) one or more (smaller) parts or fragments as described herein.

For a general description of immunoglobulin single variable domains, reference is made to the further description below, as well as to the prior art cited herein. In this respect, it should however be noted that this description and the prior art mainly describes immunoglobulin single variable domains of the so-called “V_(H)3 class” (i e immunoglobulin single variable domains with a high degree of sequence homology to human germline sequences of the V_(H)3 class such as DP-47, DP-51 or DP-29), which form a preferred aspect of this invention. It should however be noted that the invention in its broadest sense generally covers any type of immunoglobulin single variable domains directed against CXCR7 and in particular human CXCR7 (SEQ ID NO: 1), and for example also covers the immunoglobulin single variable domains belonging to the so-called “V_(H)4 class” (i.e. immunoglobulin single variable domains with a high degree of sequence homology to human germline sequences of the V_(H)4 class such as DP-78), as for example described in WO 07/118670.

Generally, immunoglobulin single variable domains (in particular V_(HH) sequences and sequence optimized immunoglobulin single variable domains) can in particular be characterized by the presence of one or more “Hallmark residues” (as described herein) in one or more of the framework sequences (again as further described herein).

Thus, generally, an immunoglobulin single variable domain can be defined as an amino acid sequence with the (general) structure FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4 in which FR1 to FR4 refer to framework regions 1 to 4, respectively, and in which CDR1 to CDR3 refer to the complementarity determining regions 1 to 3, respectively.

In a preferred aspect, the invention provides polypeptides comprising at least an immunoglobulin single variable domain that is an amino acid sequence with the (general) structure FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4 in which FR1 to FR4 refer to framework regions 1 to 4, respectively, and in which CDR1 to CDR3 refer to the complementarity determining regions 1 to 3, respectively, and in which:

-   i) at least one of the amino acid residues at positions 11, 37, 44,     45, 47, 83, 84, 103, 104 and 108 according to the Kabat numbering     are chosen from the Hallmark residues mentioned in Table A-1 below;     and in which: -   ii) said amino acid sequence has at least 80%, more preferably 90%,     even more preferably 95% amino acid identity with at least one of     the immunoglobulin single variable domains as shown in WO     2009/138519 (see SEQ ID NO's: 1 to 125 in WO 2009/138519), in which     for the purposes of determining the degree of amino acid identity,     the amino acid residues that form the CDR sequences (indicated with     X in the sequences) are disregarded; and in which: -   iii) the CDR sequences are generally as further defined herein (e.g.     the CDR1, CDR2 and CDR3 in a combination as provided in Table (B-2),     note that the CDR definitions are calculated according to the Kabat     numbering system).

TABLE A-1 Hallmark Residues in VHHs Posi- tion Human V_(H)3 Hallmark Residues  11 L, V; pre- L, S, V, M, W, F, T, Q, E, A, R, G, K, Y, N, P, dominantly L I; preferably L  37 V, I, F; F⁽¹⁾, Y, V, L, A, H, S, I, W, C, N, G, D, T, P, usually V preferably F⁽¹⁾ or Y  44⁽⁸⁾ G E⁽³⁾, Q⁽³⁾, G⁽²⁾, D, A, K, R, L, P, S, V, H, T, N, W, M, I; preferably G⁽²⁾, E⁽³⁾ or Q⁽³⁾; most preferably G⁽²⁾ or Q⁽³⁾.  45⁽⁸⁾ L L⁽²⁾, R⁽³⁾, P, H, F, G, Q, S, E, T, Y, C, I, D, V; preferably L⁽²⁾ or R⁽³⁾  47⁽⁸⁾ W, Y F⁽¹⁾, L⁽¹⁾ or W⁽²⁾ G, I, S, A, V, M, R, Y, E, P, T, C, H, K, Q, N, D; preferably W⁽²⁾, L⁽¹⁾ or F⁽¹⁾  83 R or K; R, K⁽⁵⁾, T, E⁽⁵⁾, Q, N, S, I, V, G, M, L, A, D, Y, usually R H; preferably K or R; most preferably K  84 A, T, D; pre- P⁽⁵⁾, S, H, L, A, V, I, T, F, D, R, Y, N, Q, G, E; dominantly A preferably P 103 W W⁽⁴⁾, R⁽⁶⁾, G, S, K, A, M, Y, L, F, T, N, V, Q, P⁽⁶⁾, E, C; preferably W 104 G G, A, S, T, D, P, N, E, C, L; preferably G 108 L, M or T; pre- Q, L⁽⁷⁾, R, P, E, K, S, T, M, A, H; preferably dominantly L Q or L⁽⁷⁾ ⁽¹⁾In particular, but not exclusively, in combination with KERE (SEQ ID NO: 91) or KQRE (SEQ ID NO: 92) at positions 43-46. ⁽²⁾Usually as GLEW (SEQ ID NO: 93) at positions 44-47. ⁽³⁾Usually as KERE (SEQ ID NO: 91) or KQRE (SEQ ID NO: 92) at positions 43-46, e.g. as KEREL (SEQ ID NO: 94), KEREF (SEQ ID NO: 95), KQREL (SEQ ID NO: 96), KQREF (SEQ ID NO: 97), KEREG (SEQ ID NO: 98), KQREW (SEQ ID NO: 99) or KQREG (SEQ ID NO: 100) at positions 43-47. Alternatively, also sequences such as TERE (SEQ ID NO: 101) (for example TEREL (SEQ ID NO: 102)), TQRE (SEQ ID NO: 103) (for example TQREL (SEQ ID NO: 104)), KECE (SEQ ID NO: 105) (for example KECEL (SEQ ID NO: 106) or KECER (SEQ ID NO: 107)), KQCE (SEQ ID NO: 108) (for example KQCEL (SEQ ID NO: 109)), RERE (SEQ ID NO: 110) (for example REREG (SEQ ID NO: 111)), RQRE (SEQ ID NO: 112) (for example RQREL (SEQ ID NO: 113), RQREF (SEQ ID NO: 114) or RQREW (SEQ ID NO: 115)), QERE (SEQ ID NO: 116) (for example QEREG (SEQ ID NO: 117)), QQRE (SEQ ID NO: 118), (for example QQREW (SEQ ID NO: 119), QQREL (SEQ ID NO: 120) or QQREF (SEQ ID NO: 121), KGRE (SEQ ID NO: 122) (for example KGREG (SEQ ID NO: 123)), KDRE (SEQ ID NO: 124) (for example KDREV (SEQ ID NO: 125)) are possible. Some other possible, but less preferred sequences include for example DECKL (SEQ ID NO: 126) and NVCEL (SEQ ID NO: 127). ⁽⁴⁾With both GLEW (SEQ ID NO: 93) at positions 44-47 and KERE (SEQ ID NO: 91) or KQRE (SEQ ID NO: 92) at positions 43-46. ⁽⁵⁾Often as KP or EP at positions 83-84 of naturally occurring V_(HH) domains. ⁽⁶⁾In particular, but not exclusively, in combination with GLEW (SEQ ID NO: 93) at positions 44-47. ⁽⁷⁾With the proviso that when positions 44-47 are GLEW (SEQ ID NO: 93), position 108 is always Q in (non-humanized) V_(HH) sequences that also contain a W at 103. ⁽⁸⁾The GLEW group also contains GLEW-like sequences at positions 44-47, such as for example GVEW (SEQ ID NO: 128), EPEW (SEQ ID NO: 129), GLER (SEQ ID NO: 130), DQEW (SEQ ID NO: 131), DLEW (SEQ ID NO: 132), GIEW (SEQ ID NO: 133), ELEW (SEQ ID NO: 134), GPEW (SEQ ID NO: 135), EWLP (SEQ ID NO: 136), and GPER (SEQ ID NO: 137).

Again, such immunoglobulin single variable domains may be derived in any suitable manner and from any suitable source, and may for example be naturally occurring V_(HH) sequences (i.e. from a suitable species of Camelid, e.g. llama) or synthetic or semi-synthetic VHs or VLs (e.g. from human). Such immunoglobulin single variable domains may include “humanized” or otherwise “sequence optimized” VHHs, “camelized” immunoglobulin sequences (and in particular camelized heavy chain variable domain sequences, i.e. camelized VHs), as well as human VHs, human VLs, camelid VHHs that have been altered by techniques such as affinity maturation (for example, starting from synthetic, random or naturally occurring immunoglobulin sequences), CDR grafting, veneering, combining fragments derived from different immunoglobulin sequences, PCR assembly using overlapping primers, and similar techniques for engineering immunoglobulin sequences well known to the skilled person; or any suitable combination of any of the foregoing as further described herein.

In a further preferred aspect, the invention provides polypeptides comprising one immunoglobulin single variable domain with amino acid sequence selected from the group consisting of amino acid sequences with SEQ ID NO's: 39 to 43 (see Table B-2) and one immunoglobulin single variable domain with amino acid sequence selected from the group consisting of moieties providing an increased half-life (see below).

In a further preferred aspect, the invention provides polypeptides comprising at least an immunoglobulin single variable domain with amino acid sequence selected from the group consisting of amino acid sequences that essentially consist of 4 framework regions (FR1 to FR4, respectively) and 3 complementarity determining regions (CDR1 to CDR3, respectively), in which the CDR sequences of said amino acid sequences have at least 70% amino acid identity, preferably at least 80% amino acid identity, more preferably at least 90% amino acid identity, such as 95% amino acid identity or more or even essentially 100% amino acid identity with the CDR sequences of at least one of the immunoglobulin single variable domains of SEQ ID NO's: 39 to 43 (see Tables B-2 and B-3). This degree of amino acid identity can for example be determined by determining the degree of amino acid identity (in a manner described herein) between said amino acid sequence and one or more of the sequences of SEQ ID NO's: 39 to 43 (see Tables B-2 and B-3), in which the amino acid residues that form the framework regions are disregarded. Such polypeptides and/or immunoglobulin single variable domains of the invention may further provide the following:

-   1. Polypeptides comprising at least one (preferably one)     immunoglobulin single variable domain that is directed against (as     defined herein) CXCR7 and in particular human CXCR7 (SEQ ID NO: 1)     and that has at least 80%, preferably at least 85%, such as 90% or     95% or more sequence identity with at least one of the     immunoglobulin single variable domains of SEQ ID NO's: 39 to 43 (see     Table B-3); -   2. Polypeptides comprising at least one (preferably one)     immunoglobulin single variable domain that is directed against (as     defined herein) CXCR7 and in particular human CXCR7 (SEQ ID NO: 1)     and that cross-block (as defined herein) the binding of at least one     of the immunoglobulin single variable domains of SEQ ID NO's: 39 to     43 (see Table B-3) to CXCR7 and in particular human CXCR7 (SEQ ID     NO: 1) and/or that compete with at least one of the immunoglobulin     single variable domains of SEQ ID NO's: 39 to 43 (see Table B-3) for     binding to CXCR7 and in particular human CXCR7 (SEQ ID NO: 1); and -   3. which immunoglobulin single variable domains may be as further     described herein; as well as polypeptides of the invention that     comprise one or more (preferably one) of such immunoglobulin single     variable domains (which may be as further described herein, and may     for example be bispecific (e.g. also bind to serum albumin) and/or     biparatopic polypeptides as described herein), and nucleic acid     sequences that encode such immunoglobulin single variable domains     and polypeptides. Such immunoglobulin single variable domains and     polypeptides do not include any naturally occurring ligands.

The polypeptides of the invention comprise or essentially consist of at least one immunoglobulin single variable domain of the invention. Some preferred, but non-limiting examples of immunoglobulin single variable domains of the invention are given in SEQ ID NO's: 39 to 43 (see Table B-3).

1.2. Serum Albumin Binding Building Blocks or Other Building Blocks Increasing Half-Life

In another aspect, the invention relates to a compound or construct, and in particular to a protein or polypeptide (also referred to herein as a “compound of the invention” or “polypeptide of the invention”, respectively) that comprises or essentially consists of one or more (preferably one) immunoglobulin single variable domains directed to human CXCR7 (or suitable fragments thereof), and optionally further comprises one or more other groups, residues, moieties or binding units. As will become clear to the skilled person from the further disclosure herein, such further groups, residues, moieties, binding units or immunoglobulin single variable domains may or may not provide further functionality to the amino acid sequence of the invention (and/or to the compound or construct in which it is present) and may or may not modify the properties of the amino acid sequence of the invention.

As will be clear from the further description above and herein, this means that the immunoglobulin single variable domains of the invention can be used as “building blocks” to form polypeptides of the invention, i.e. by suitably combining them with other groups, residues, moieties or binding units, in order to form compounds or constructs as described herein (such as, without limitations, the biparatopic, bi/multivalent and bi/multispecific polypeptides of the invention described herein) which combine within one molecule one or more desired properties or biological functions.

The compounds or polypeptides of the invention can generally be prepared by a method which comprises at least one step of suitably linking the one or more immunoglobulin single variable domains of the invention to the one or more further groups, residues, moieties or binding units, optionally via the one or more suitable linkers, so as to provide the compound or polypeptide of the invention. Polypeptides of the invention can also be prepared by a method which generally comprises at least the steps of providing a nucleic acid that encodes a polypeptide of the invention, expressing said nucleic acid in a suitable manner, and recovering the expressed polypeptide of the invention. Such methods can be performed in a manner known per se, which will be clear to the skilled person, for example on the basis of the methods and techniques further described herein.

The process of designing/selecting and/or preparing a compound or polypeptide of the invention, starting from an amino acid sequence of the invention, is also referred to herein as “formatting” said amino acid sequence of the invention; and an amino acid of the invention that is made part of a compound or polypeptide of the invention is said to be “formatted” or to be “in the format of” said compound or polypeptide of the invention. Examples of ways in which an amino acid sequence of the invention can be formatted and examples of such formats will be clear to the skilled person based on the disclosure herein; and such formatted immunoglobulin single variable domains form a further aspect of the invention.

For example, such further groups, residues, moieties or binding units may be one or more additional immunoglobulin single variable domains, such that the compound or construct is a (fusion) protein or (fusion) polypeptide. In a preferred but non-limiting aspect, said one or more other groups, residues, moieties or binding units are immunoglobulin sequences. Even more preferably, said one or more other groups, residues, moieties or binding units are chosen from the group consisting of domain antibodies, immunoglobulin single variable domains that are suitable for use as a domain antibody, single domain antibodies, immunoglobulin single variable domains that are suitable for use as a single domain antibody, “dAb”'s, immunoglobulin single variable domains that are suitable for use as a dAb, or Nanobodies. Alternatively, such groups, residues, moieties or binding units may for example be chemical groups, residues, moieties, which may or may not by themselves be biologically and/or pharmacologically active. For example, and without limitation, such groups may be linked to the one or more immunoglobulin single variable domains of the invention so as to provide a “derivative” of an amino acid sequence or polypeptide of the invention, as further described herein.

Also within the scope of the present invention are compounds or constructs, that comprises or essentially consists of one or more derivatives as described herein, and optionally further comprises one or more other groups, residues, moieties or binding units, optionally linked via one or more linkers. Preferably, said one or more other groups, residues, moieties or binding units are immunoglobulin single variable domains. In the compounds or constructs described above, the one or more immunoglobulin single variable domains of the invention and the one or more groups, residues, moieties or binding units may be linked directly to each other and/or via one or more suitable linkers or spacers. For example, when the one or more groups, residues, moieties or binding units are immunoglobulin single variable domains, the linkers may also be immunoglobulin single variable domains, so that the resulting compound or construct is a fusion (protein) or fusion (polypeptide).

In one specific, but non-limiting aspect of the invention, which will be further described herein, the polypeptides of the invention have an increased half-life in serum (as further described herein) compared to the immunoglobulin single variable domain from which they have been derived. For example, an immunoglobulin single variable domain of the invention may be linked (chemically or otherwise) to one or more groups or moieties that extend the half-life (such as PEG), so as to provide a derivative of an amino acid sequence of the invention with increased half-life.

In one specific aspect of the invention, a compound of the invention or a polypeptide of the invention may have an increased half-life, compared to the corresponding amino acid sequence of the invention. Some preferred, but non-limiting examples of such compounds and polypeptides will become clear to the skilled person based on the further disclosure herein, and for example comprise immunoglobulin single variable domains or polypeptides of the invention that have been chemically modified to increase the half-life thereof (for example, by means of pegylation); immunoglobulin single variable domains of the invention that comprise at least one additional binding site for binding to a serum protein (such as serum albumin); or polypeptides of the invention that comprise at least one amino acid sequence of the invention that is linked to at least one moiety (and in particular at least one amino acid sequence) that increases the half-life of the amino acid sequence of the invention. Examples of polypeptides of the invention that comprise such half-life extending moieties or immunoglobulin single variable domains will become clear to the skilled person based on the further disclosure herein; and for example include, without limitation, polypeptides in which the one or more immunoglobulin single variable domains of the invention are suitably linked to one or more serum proteins or fragments thereof (such as (human) serum albumin or suitable fragments thereof) or to one or more binding units that can bind to serum proteins (such as, for example, domain antibodies, immunoglobulin single variable domains that are suitable for use as a domain antibody, single domain antibodies, immunoglobulin single variable domains that are suitable for use as a single domain antibody, “dAb”'s, immunoglobulin single variable domains that are suitable for use as a dAb, or Nanobodies that can bind to serum proteins such as serum albumin (such as human serum albumin), serum immunoglobulins such as IgG, or transferrine; reference is made to the further description and references mentioned herein); polypeptides in which an amino acid sequence of the invention is linked to an Fc portion (such as a human Fc) or a suitable part or fragment thereof; or polypeptides in which the one or more immunoglobulin single variable domains of the invention are suitable linked to one or more small proteins or peptides that can bind to serum proteins (such as, without limitation, the proteins and peptides described in WO 91/01743, WO 01/45746, WO 02/076489, WO2008/068280, WO2009/127691).

Generally, the compounds or polypeptides of the invention with increased half-life preferably have a half-life that is at least 1.5 times, preferably at least 2 times, such as at least 5 times, for example at least 10 times or more than 20 times, greater than the half-life of the corresponding amino acid sequence of the invention per se. For example, the compounds or polypeptides of the invention with increased half-life may have a half-life e.g. in humans that is increased with more than 1 hours, preferably more than 2 hours, more preferably more than 6 hours, such as more than 12 hours, or even more than 24, 48 or 72 hours, compared to the corresponding amino acid sequence of the invention per se.

In a preferred, but non-limiting aspect of the invention, such compounds or polypeptides of the invention have a serum half-life e.g. in humans that is increased with more than 1 hours, preferably more than 2 hours, more preferably more than 6 hours, such as more than 12 hours, or even more than 24, 48 or 72 hours, compared to the corresponding amino acid sequence of the invention per se.

In another preferred, but non-limiting aspect of the invention, such compounds or polypeptides of the invention exhibit a serum half-life in human of at least about 12 hours, preferably at least 24 hours, more preferably at least 48 hours, even more preferably at least 72 hours or more. For example, compounds or polypeptides of the invention may have a half-life of at least 5 days (such as about 5 to 10 days), preferably at least 9 days (such as about 9 to 14 days), more preferably at least about 10 days (such as about 10 to 15 days), or at least about 11 days (such as about 11 to 16 days), more preferably at least about 12 days (such as about 12 to 18 days or more), or more than 14 days (such as about 14 to 19 days).

In a particular preferred but non-limiting aspect of the invention, the invention provides a polypeptide of the invention comprising i) one CXCR7 binding immunoglobulin single variable domain as described herein; and ii) one or more (preferably one) serum albumin binding immunoglobulin single variable domain as described herein.

In a further preferred aspect, the invention provides a polypeptide of the invention comprising i) one CXCR7 binding immunoglobulin single variable domain as described herein; and ii) one or more (preferably one) serum albumin binding immunoglobulin single variable domain of SEQ ID NO: 2 (Table B-1).

In a further preferred aspect, the invention provides a polypeptide of the invention comprising i) one CXCR7 binding immunoglobulin single variable domain as described herein; and ii) one or more (preferably one) serum albumin binding immunoglobulin single variable domain with CDRs (defined according to the Kabat numbering) of SEQ ID NO: 2 (Table B-2, B-1).

Thus, for example, further reference (and thus incorporated by reference) is made in particular to the experimental part and further description of WO2008/068280, wherein further details on SEQ ID NO: 2 is made and e.g. the half-life of a immunoglobulin single variable domain construct containing said sequence in rhesus monkeys is disclosed.

Generally, proteins or polypeptides that comprise or essentially consist of a single immunoglobulin single variable domain will be referred to herein as “monovalent” proteins or polypeptides or as “monovalent constructs”. Proteins and polypeptides that comprise or essentially consist of two or more immunoglobulin single variable domains (such as at least two immunoglobulin single variable domains of the invention or at least one immunoglobulin single variable domain of the invention and at least one other immunoglobulin single variable domain) will be referred to herein as “multivalent” proteins or polypeptides or as “multivalent constructs”, and these may provide certain advantages compared to the corresponding monovalent immunoglobulin single variable domains of the invention. Some non-limiting examples of such multivalent constructs will become clear from the further description herein.

According to another specific, but non-limiting aspect, a polypeptide of the invention comprises or essentially consists of at least one immunoglobulin single variable domain of the invention and at least one other binding unit (i.e. directed against another epitope, antigen, target, protein or polypeptide), which is preferably also a immunoglobulin single variable domain. Such proteins or polypeptides are also referred to herein as “multispecific” proteins or polypeptides or as ‘multispecific constructs”, and these may comprise of two immunoglobulin single variable domains of the invention, such as one immunoglobulin single variable domain directed against CXCR7 and one immunoglobulin single variable domain against serum albumin Such multispecific constructs will be clear to the skilled person based on the disclosure herein; some preferred, but non-limiting examples of such multispecific immunoglobulin single variable domains are the constructs of SEQ ID NO's: 44 to 48 (see Table B-4).

According to yet another specific, but non-limiting aspect, a polypeptide of the invention comprises or essentially consists of at least one immunoglobulin single variable domain of the invention, optionally one or more further immunoglobulin single variable domains, and at least one other amino acid sequence (such as a protein or polypeptide) that confers at least one desired property to the immunoglobulin single variable domain of the invention and/or to the resulting fusion protein. Again, such fusion proteins may provide certain advantages compared to the corresponding monovalent immunoglobulin single variable domains of the invention such as e.g. may provide an increased half-life.

In the above constructs, the one or more immunoglobulin single variable domains and/or other immunoglobulin single variable domains may be directly linked to each other and/or suitably linked to each other via one or more linker sequences. Some suitable but non-limiting examples of such linkers will become clear from the further description herein.

In one embodiment, the linker sequence joining the immunoglobulin single variable domains are SEQ ID NO: 49 to 58—see Table B-5, or a combination of both, or as known in the art.

According to yet another specific, but non-limiting aspect, a polypeptide of the invention may for example be chosen from the group consisting of immunoglobulin single variable domains that have more than 80%, preferably more than 90%, more preferably more than 95%, such as 99% or more “sequence identity” (as defined herein) with one or more of the immunoglobulin single variable domains of SEQ ID NO's: 39 to 43 (see Table B-3), in which the polypeptides are preferably as further defined herein, i.e. in the preferred format of one immunoglobulin single variable domain directed against CXCR7 and one immunoglobulin singe variable domain directed against serum albumin

According to yet another specific, but non-limiting aspect, a polypeptide of the invention may for example be chosen from the group consisting of polypeptides that have more than 80%, preferably more than 90%, more preferably more than 95%, such as 99% or more “sequence identity” (as defined herein) with one or more of the polypeptides of SEQ ID NO's: 44 to 48 (see Table B-4). Some illustrative non-limiting examples of biparatopic and bispecific polypeptides of the invention are given in SEQ ID NO's: 78 to 89.

1.3. Compositions and Pharmaceutical Compositions of the Invention

Generally, for pharmaceutical use, the polypeptides of the invention may be formulated as a pharmaceutical preparation or composition comprising at least one polypeptide of the invention and at least one pharmaceutically acceptable carrier, diluent or excipient and/or adjuvant, and optionally one or more further pharmaceutically active polypeptides and/or compounds. By means of non-limiting examples, such a formulation may be in a form suitable for oral administration, for parenteral administration (such as by intravenous, intramuscular or subcutaneous injection or intravenous infusion), for topical administration, for administration by inhalation, by a skin patch, by an implant, by a suppository, etc wherein which the parenteral administration is preferred. Such suitable administration forms—which may be solid, semi-solid or liquid, depending on the manner of administration—as well as methods and carriers for use in the preparation thereof, will be clear to the skilled person, and are further described herein. Such a pharmaceutical preparation or composition will generally be referred to herein as a “pharmaceutical composition”. A pharmaceutical preparation or composition for use in a non-human organism will generally be referred to herein as a “veterinary composition”.

Thus, in a further aspect, the invention relates to a pharmaceutical composition that contains at least one amino acid of the invention, at least one polypeptide of the invention or at least one polypeptide of the invention and at least one suitable carrier, diluent or excipient (i.e., suitable for pharmaceutical use), and optionally one or more further active substances.

Generally, the polypeptides of the invention can be formulated and administered in any suitable manner known per se. Reference is for example made to the general background art cited above (and in particular to WO 04/041862, WO 04/041863, WO 04/041865, WO 04/041867 and WO 08/020079) as well as to the standard handbooks, such as Remington's Pharmaceutical Sciences, 18^(th) Ed., Mack Publishing Company, USA (1990), Remington, the Science and Practice of Pharmacy, 21th Edition, Lippincott Williams and Wilkins (2005); or the Handbook of Therapeutic Antibodies (S. Dubel, Ed.), Wiley, Weinheim, 2007 (see for example pages 252-255).

The polypeptides of the invention may be formulated and administered in any manner known per se for conventional antibodies and antibody fragments (including ScFv's and diabodies) and other pharmaceutically active proteins. Such formulations and methods for preparing the same will be clear to the skilled person, and for example include preparations suitable for parenteral administration (for example intravenous, intraperitoneal, subcutaneous, intramuscular, intraluminal, intra-arterial or intrathecal administration) or for topical (i.e., transdermal or intradermal) administration.

Preparations for parenteral administration may for example be sterile solutions, suspensions, dispersions or emulsions that are suitable for infusion or injection. Suitable carriers or diluents for such preparations for example include, without limitation, those mentioned on page 143 of WO 08/020079. In one embodiment, the preparation is an aqueous solution or suspension.

The polypeptides of the invention can be administered using gene therapy methods of delivery. See, e.g., U.S. Pat. No. 5,399,346, which is incorporated by reference for its gene therapy delivery methods. Using a gene therapy method of delivery, primary cells transfected with the gene encoding an amino acid sequence, polypeptide of the invention can additionally be transfected with tissue specific promoters to target specific organs, tissue, grafts, tumors, or cells and can additionally be transfected with signal and stabilization sequences for subcellularly localized expression.

Thus, the polypeptides of the invention may be systemically administered, e.g., orally, in combination with a pharmaceutically acceptable vehicle such as an inert diluent or an assimilable edible carrier. They may be enclosed in hard or soft shell gelatin capsules, may be compressed into tablets, or may be incorporated directly with the food of the patient's diet. For oral therapeutic administration, the polypeptides of the invention may be combined with one or more excipients and used in the form of ingestible tablets, buccal tablets, troches, capsules, elixirs, suspensions, syrups, wafers, and the like. Such compositions and preparations should contain at least 0.1% of the polypeptide of the invention. Their percentage in the compositions and preparations may, of course, be varied and may conveniently be between about 2 to about 60% of the weight of a given unit dosage form. The amount of the polypeptide of the invention in such therapeutically useful compositions is such that an effective dosage level will be obtained.

For local administration at the site of tumor resection, the polypeptides of the invention may be used in biodegradable polymeric drug delivery systems, slow release poly(lactic-co-glycolic acid formulations and the like (Hart et al., Cochrane Database Syst Rev. 2008 Jul. 16; (3): CD007294).

In a further preferred aspect of the invention, the polypeptides of the invention, such as a polypeptide consisting essentially of one monovalent anti-human CXCR7 immunoglobulin single variable domain and of one monovalent anti-human serum albumin immunoglobulin single variable domain linked by a GS linker, may have a beneficial distribution and kinetics profile in solid tumors compared to conventional antibodies such as e.g. IgG

The tablets, troches, pills, capsules, and the like may also contain binders, excipients, disintegrating agents, lubricants and sweetening or flavoring agents, for example those mentioned on pages 143-144 of WO 08/020079. When the unit dosage form is a capsule, it may contain, in addition to materials of the above type, a liquid carrier, such as a vegetable oil or a polyethylene glycol. Various other materials may be present as coatings or to otherwise modify the physical form of the solid unit dosage form. For instance, tablets, pills, or capsules may be coated with gelatin, wax, shellac or sugar and the like. A syrup or elixir may contain the polypeptides of the invention, sucrose or fructose as a sweetening agent, methyl and propylparabens as preservatives, a dye and flavoring such as cherry or orange flavor. Of course, any material used in preparing any unit dosage form should be pharmaceutically acceptable and substantially non-toxic in the amounts employed. In addition, the polypeptides of the invention may be incorporated into sustained-release preparations and devices.

Preparations and formulations for oral administration may also be provided with an enteric coating that will allow the constructs of the invention to resist the gastric environment and pass into the intestines. More generally, preparations and formulations for oral administration may be suitably formulated for delivery into any desired part of the gastrointestinal tract. In addition, suitable suppositories may be used for delivery into the gastrointestinal tract.

The polypeptides of the invention may also be administered intravenously or intraperitoneally by infusion or injection. Particular examples are as further described on pages 144 and 145 of WO 08/020079.

For topical administration, the polypeptides of the invention may be applied in pure form, i.e., when they are liquids. However, it will generally be desirable to administer them to the skin as compositions or formulations, in combination with a dermatologically acceptable carrier, which may be a solid or a liquid. Particular examples are as further described on page 145 of WO 08/020079.

Generally, the concentration of the polypeptides of the invention in a liquid composition, such as a lotion, will be from about 0.1-25 wt-%, preferably from about 0.5-10 wt-%. The concentration in a semi-solid or solid composition such as a gel or a powder will be about 0.1-5 wt-%, preferably about 0.5-2.5 wt-%.

The amount of the polypeptides of the invention required for use in treatment will vary not only with the particular polypeptide selected but also with the route of administration, the nature of the condition being treated and the age and condition of the patient and will be ultimately at the discretion of the attendant physician or clinician. Also the dosage of the polypeptides of the invention varies depending on the target cell, tumor, tissue, graft, or organ.

The desired dose may conveniently be presented in a single dose or as divided doses administered at appropriate intervals, for example, as two, three, four or more sub-doses per day. The sub-dose itself may be further divided, e.g., into a number of discrete loosely spaced administrations.

An administration regimen could include long-term, daily treatment. By “long-term” is meant at least two weeks and preferably, several weeks, months, or years of duration. Necessary modifications in this dosage range may be determined by one of ordinary skill in the art using only routine experimentation given the teachings herein. See Remington's Pharmaceutical Sciences (Martin, E. W., ed. 4), Mack Publishing Co., Easton, Pa. The dosage can also be adjusted by the individual physician in the event of any complication.

In another aspect, the invention relates to a method for the prevention and/or treatment of at least one diseases and disorders associated with CXCR7, said method comprising administering, to a subject in need thereof, a pharmaceutically active amount of a polypeptide of the invention, and/or of a pharmaceutical composition comprising the same.

In the context of the present invention, the term “prevention and/or treatment” not only comprises preventing and/or treating the disease, but also generally comprises preventing the onset of the disease, slowing or reversing the progress of disease, preventing or slowing the onset of one or more symptoms associated with the disease, reducing and/or alleviating one or more symptoms associated with the disease, reducing the severity and/or the duration of the disease and/or of any symptoms associated therewith and/or preventing a further increase in the severity of the disease and/or of any symptoms associated therewith, preventing, reducing or reversing any physiological damage caused by the disease, and generally any pharmacological action that is beneficial to the patient being treated.

The subject to be treated may be any warm-blooded animal, but is in particular a mammal, and more in particular a human being. As will be clear to the skilled person, the subject to be treated will in particular be a person suffering from, or at risk of, the diseases and disorders mentioned herein.

The invention relates to a method for the prevention and/or treatment of at least one disease or disorder that is associated with CXCR7, with its biological or pharmacological activity, and/or with the biological pathways or signaling in which CXCR7 is involved, said method comprising administering, to a subject in need thereof, a pharmaceutically active amount of an amino acid sequence of the invention, of a Polypeptide of the invention, of a polypeptide of the invention, and/or of a pharmaceutical composition comprising the same. In one embodiment, the invention relates to a method for the prevention and/or treatment of at least one disease or disorder that can be treated by modulating CXCR7, its biological or pharmacological activity, and/or the biological pathways or signaling in which CXCR7 are involved, said method comprising administering, to a subject in need thereof, a pharmaceutically active amount of a polypeptide of the invention, and/or of a pharmaceutical composition comprising the same. In one embodiment, said pharmaceutically effective amount may be an amount that is sufficient to modulate CXCR7, its biological or pharmacological activity, and/or the biological pathways or signaling in which CXCR7 is involved; and/or an amount that provides a level of the polypeptide of the invention in the circulation that is sufficient to modulate CXCR7, its biological or pharmacological activity, and/or the biological pathways or signaling in which CXCR7 is involved.

In one embodiment the invention relates to a method for the prevention and/or treatment of at least one disease or disorder that can be prevented and/or treated by administering a polypeptide of the invention, or a nucleotide construct of the invention encoding the same, and/or of a pharmaceutical composition comprising the same, to a patient. In one embodiment, the method comprises administering a pharmaceutically active amount of a polypeptide of the invention, or a nucleotide construct of the invention encoding the same, and/or of a pharmaceutical composition comprising the same to a subject in need thereof.

In one embodiment the invention relates to a method for the prevention and/or treatment of at least one disease or disorder that can be prevented and/or treated by inhibiting binding of CXCL12 and/or CXCL11 to CXCR7 in specific cells or in a specific tissue of a subject to be treated (and in particular, by inhibiting binding of CXCL12 and/or CXCL11 to CXCR7 in cancer cells or in a tumor present in the subject to be treated), said method comprising administering a pharmaceutically active amount of a polypeptide of the invention, or a nucleotide construct of the invention encoding the same, and/or of a pharmaceutical composition comprising the same, to a subject in need thereof.

In one embodiment, the invention relates to a method for the prevention and/or treatment of at least one disease or disorder chosen from the group consisting of the diseases and disorders listed herein, said method comprising administering, to a subject in need thereof, a polypeptide of the invention, or a nucleotide construct of the invention encoding the same, and/or of a pharmaceutical composition comprising the same.

In one embodiment, the invention relates to a method for immunotherapy, and in particular for passive immunotherapy, which method comprises administering, to a subject suffering from or at risk of the diseases and disorders mentioned herein, a pharmaceutically active amount of a polypeptide of the invention, or a nucleotide construct of the invention encoding the same, and/or of a pharmaceutical composition comprising the same.

In the above methods, the amino acid sequences, polypeptides of the invention and/or the compositions comprising the same can be administered in any suitable manner, depending on the specific pharmaceutical formulation or composition to be used. Thus, the polypeptides of the invention and/or the compositions comprising the same can for example be administered orally, intraperitoneally (e.g. intravenously, subcutaneously, intramuscularly, or via any other route of administration that circumvents the gastrointestinal tract), intranasally, transdermally, topically, by means of a suppository, by inhalation, again depending on the specific pharmaceutical formulation or composition to be used. The clinician will be able to select a suitable route of administration and a suitable pharmaceutical formulation or composition to be used in such administration, depending on the disease or disorder to be prevented or treated and other factors well known to the clinician.

The polypeptides of the invention and/or the compositions comprising the same are administered according to a regime of treatment that is suitable for preventing and/or treating the disease or disorder to be prevented or treated. The clinician will generally be able to determine a suitable treatment regimen, depending on factors such as the disease or disorder to be prevented or treated, the severity of the disease to be treated and/or the severity of the symptoms thereof, the polypeptide of the invention to be used, the specific route of administration and pharmaceutical formulation or composition to be used, the age, gender, weight, diet, general condition of the patient, and similar factors well known to the clinician.

Generally, the treatment regimen will comprise the administration of one or more polypeptides of the invention, or of one or more compositions comprising the same, in one or more pharmaceutically effective amounts or doses. The specific amount(s) or doses to administered can be determined by the clinician, again based on the factors cited above.

Generally, for the prevention and/or treatment of the diseases and disorders mentioned herein and depending on the specific disease or disorder to be treated, the potency of the specific polypeptide of the invention to be used, the specific route of administration and the specific pharmaceutical formulation or composition used, the polypeptides of the invention will generally be administered in an amount between 1 gram and 0.01 microgram per kg body weight per day, preferably between 0.1 gram and 0.1 microgram per kg body weight per day, such as about 1, 10, 100 or 1000 microgram per kg body weight per day, either continuously (e.g. by infusion), as a single daily dose or as multiple divided doses during the day. The clinician will generally be able to determine a suitable daily dose, depending on the factors mentioned herein. It will also be clear that in specific cases, the clinician may choose to deviate from these amounts, for example on the basis of the factors cited above and his expert judgment. Generally, some guidance on the amounts to be administered can be obtained from the amounts usually administered for comparable conventional antibodies or antibody fragments against the same target administered via essentially the same route, taking into account however differences in affinity/avidity, efficacy, biodistribution, half-life and similar factors well known to the skilled person.

In one embodiment, a single contiguous polypeptide of the invention will be used. In one embodiment two or more polypeptides of the invention are provided in combination.

The polypeptides of the invention may be used in combination with one or more further pharmaceutically active compounds or principles, i.e., as a combined treatment regimen, which may or may not lead to a synergistic effect. Again, the clinician will be able to select such further compounds or principles, as well as a suitable combined treatment regimen, based on the factors cited above and his expert judgment.

In particular, the polypeptides of the invention may be used in combination with other pharmaceutically active compounds or principles that are or can be used for the prevention and/or treatment of the diseases and disorders cited herein, as a result of which a synergistic effect may or may not be obtained. Examples of such compounds and principles, as well as routes, methods and pharmaceutical formulations or compositions for administering them will be clear to the clinician, and generally include the cytostatic active principles usually applied for the treatment of the tumor to be treated.

Specific contemplated combinations for use with the polypeptides of the invention for oncology include, but are not limited to, e.g., CXCR4 antagonists such as e.g. AMD3100, other chemokine receptor antagonists, TAXOL® (paclitaxel); gemcitobine; cisplatin; cIAP inhibitors (such as inhibitors to cIAP1, cIAP2 and/or XIAP); MEK inhibitors including but not limited to, e.g., U0126, PD0325901; bRaf inhibitors including but not limited to, e.g., RAF265; and mTOR inhibitors including but not limited to, e.g., RAD001; VEGF inhibitors including but not limited to e.g. bevacizumab, sutinib and sorafenib; Her 2 inhibitors including but not limited to e.g. trastuzumab and lapatinib; PDGFR, FGFR, src, JAK, STAT and/or GSK3 inhibitors; selective estrogen receptor modulators including but not limited to tamoxifen; estrogen receptor downregulators including but not limited to fulvestrant. Specific contemplated combinations for use with the polypeptides of the invention for inflammatory conditions include, but are not limited to, e.g., interferon beta 1 alpha and beta, natalizumab; TNF alpha antagonists including but not limited to e.g. infliximab, adalimumab, certolizumab pegol, etanercept; disease-modifying antirheumatic drugs such as e.g. methotrexate (MTX); glucocortioids including but not limited to e.g. hydrocortisone; Nonsteroidal anti-inflammatory drugs including but not limited to e.g. ibuprofen, sulindac.

Other specific compounds/polypeptides that could be used in combination (therapy) with the compounds/polypeptides of the invention are the amino acid sequences and polypeptides directed against CXCR4 that are described in the international application WO 09/138519 by Ablynx N.V., the non-prepublished U.S. application 61/358,495 by Ablynx N.V. filed on Jun. 25, 2010; the PCT application PCT/EP210/064766 by Ablynx N.V. filed on Oct. 4, 2010; and/or the PCT application PCT/EP2011/050156 by Ablynx N.V. filed on Jan. 7, 2011.

When two or more substances or principles are to be used as part of a combined treatment regimen, they can be administered via the same route of administration or via different routes of administration, at essentially the same time or at different times (e.g. essentially simultaneously, consecutively, or according to an alternating regime). When the substances or principles are to be administered simultaneously via the same route of administration, they may be administered as different pharmaceutical formulations or compositions or part of a combined pharmaceutical formulation or composition, as will be clear to the skilled person.

Also, when two or more active substances or principles are to be used as part of a combined treatment regimen, each of the substances or principles may be administered in the same amount and according to the same regimen as used when the compound or principle is used on its own, and such combined use may or may not lead to a synergistic effect. However, when the combined use of the two or more active substances or principles leads to a synergistic effect, it may also be possible to reduce the amount of one, more or all of the substances or principles to be administered, while still achieving the desired therapeutic action. This may for example be useful for avoiding, limiting or reducing any unwanted side-effects that are associated with the use of one or more of the substances or principles when they are used in their usual amounts, while still obtaining the desired pharmaceutical or therapeutic effect.

The effectiveness of the treatment regimen used according to the invention may be determined and/or followed in any manner known per se for the disease or disorder involved, as will be clear to the clinician. The clinician will also be able, where appropriate and on a case-by-case basis, to change or modify a particular treatment regimen, so as to achieve the desired therapeutic effect, to avoid, limit or reduce unwanted side-effects, and/or to achieve an appropriate balance between achieving the desired therapeutic effect on the one hand and avoiding, limiting or reducing undesired side effects on the other hand.

Generally, the treatment regimen will be followed until the desired therapeutic effect is achieved and/or for as long as the desired therapeutic effect is to be maintained. Again, this can be determined by the clinician.

In another aspect, the invention relates to the use of polypeptide of the invention in the preparation of a pharmaceutical composition for prevention and/or treatment of at least one diseases and disorders associated with CXCR7; and/or for use in one or more of the methods of treatment mentioned herein.

The subject to be treated may be any warm-blooded animal, but is in particular a mammal, and more in particular a human being. In veterinary applications, the subject to be treated includes any animal raised for commercial purposes or kept as a pet. As will be clear to the skilled person, the subject to be treated will in particular be a person suffering from, or at risk of, the diseases and disorders mentioned herein.

The invention relates to the use of a polypeptide of the invention, or a nucleotide encoding the same, in the preparation of a pharmaceutical composition for the prevention and/or treatment of at least one disease or disorder that can be prevented and/or treated by administering a polypeptide of the invention, or a nucleotide encoding the same, and/or a pharmaceutical composition of the same to a patient.

More in particular, the invention relates to the use of a polypeptide of the invention, or a nucleotide encoding the same, in the preparation of a pharmaceutical composition for the prevention and/or treatment of diseases and disorders associated with CXCR7, and in particular for the prevention and treatment of one or more of the diseases and disorders listed herein.

Again, in such a pharmaceutical composition, the one or more polypeptide of the invention, or nucleotide encoding the same, and/or a pharmaceutical composition of the same, may also be suitably combined with one or more other active principles, such as those mentioned herein.

The invention also relates to a composition (such as, without limitation, a pharmaceutical composition or preparation as further described herein) for use, either in vitro (e.g. in an in vitro or cellular assay) or in vivo (e.g. in an a single cell or multicellular organism, and in particular in a mammal, and more in particular in a human being, such as in a human being that is at risk of or suffers from a disease or disorder of the invention).

In the context of the present invention, “modulating” or “to modulate” generally means reducing or inhibiting the activity of CXCR7 and in particular human CXCR7 (SEQ ID NO: 1), as measured using a suitable in vitro, cellular or in vivo assay (such as those mentioned herein). In particular, reducing or inhibiting the activity of CXCR7 and in particular human CXCR7 (SEQ ID NO: 1), as measured using a suitable in vitro, cellular or in vivo assay (such as those mentioned herein), by at least 1%, preferably at least 5%, such as at least 10% or at least 25%, for example by at least 50%, at least 60%, at least 70%, at least 80%, or 90% or more, compared to activity of CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) in the same assay under the same conditions but without the presence of the polypeptide of the invention.

Modulating may for example involve reducing or inhibiting the binding CXCR7 to one of its substrates or ligands and/or competing with natural ligands (CXCL11 and/or CXCL12), substrate for binding to CXCR7.

1.4. Generation of the Polypeptides of the Invention

The invention further relates to methods for preparing or generating the immunoglobulin single variable domains, polypeptides, nucleic acids, host cells, products and compositions described herein. Some preferred but non-limiting examples of such methods will become clear from the further description herein.

Generally, these methods may comprise the steps of:

-   a) providing a set, collection or library of immunoglobulin single     variable domains; and -   b) screening said set, collection or library of immunoglobulin     single variable domains for immunoglobulin single variable domains     that can bind to and/or have affinity for CXCR7 and in particular     human CXCR7 (SEQ ID NO: 1); -   and -   c) isolating the amino acid sequence(s) that can bind to and/or have     affinity for CXCR7 and in particular human CXCR7 (SEQ ID NO: 1).

In such a method, the set, collection or library of immunoglobulin single variable domains may be any suitable set, collection or library of immunoglobulin single variable domains. For example, the set, collection or library of immunoglobulin single variable domains may be a set, collection or library of immunoglobulin sequences (as described herein), such as a naïve set, collection or library of immunoglobulin sequences; a synthetic or semi-synthetic set, collection or library of immunoglobulin sequences; and/or a set, collection or library of immunoglobulin sequences that have been subjected to affinity maturation.

Also, in such a method, the set, collection or library of immunoglobulin single variable domains may be a set, collection or library of heavy or light chain variable domains (such as VL-, VH- or VHH domains). For example, the set, collection or library of immunoglobulin single variable domains may be a set, collection or library of domain antibodies or single domain antibodies, or may be a set, collection or library of immunoglobulin single variable domains that are capable of functioning as a domain antibody or single domain antibody.

In a preferred aspect of this method, the set, collection or library of immunoglobulin single variable domains may be an immune set, collection or library of immunoglobulin sequences, for example derived from a mammal that has been suitably immunized with CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) or with a suitable antigenic determinant based thereon or derived therefrom, such as an antigenic part, fragment, region, domain, loop or other epitope thereof. In one particular aspect, said antigenic determinant may be an extracellular part, region, domain, loop or other extracellular epitope(s).

In the above methods, the set, collection or library of immunoglobulin single variable domains may be displayed on a phage, phagemid, ribosome or suitable micro-organism (such as yeast), such as to facilitate screening. Suitable methods, techniques and host organisms for displaying and screening (a set, collection or library of) immunoglobulin single variable domains will be clear to the person skilled in the art, for example on the basis of the further disclosure herein. Reference is also made to the review by Hoogenboom in Nature Biotechnology, 23, 9, 1105-1116 (2005).

In another aspect, the method for generating immunoglobulin single variable domains comprises at least the steps of:

-   a) providing a collection or sample of cells expressing     immunoglobulin single variable domains; -   b) screening said collection or sample of cells for cells that     express an amino acid sequence that can bind to and/or have affinity     for CXCR7 and in particular human CXCR7 (SEQ ID NO: 1); -   and -   c) either (i) isolating said amino acid sequence; or (ii) isolating     from said cell a nucleic acid sequence that encodes said amino acid     sequence, followed by expressing said amino acid sequence.

In another aspect, the method for generating an amino acid sequence directed against CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) may comprise at least the steps of:

-   a) providing a set, collection or library of nucleic acid sequences     encoding immunoglobulin single variable domains; -   b) screening said set, collection or library of nucleic acid     sequences for nucleic acid sequences that encode an amino acid     sequence that can bind to and/or has affinity for CXCR7 and in     particular human CXCR7 (SEQ ID NO: 1); -   and -   c) isolating said nucleic acid sequence, followed by expressing said     amino acid sequence.

In such a method, the set, collection or library of nucleic acid sequences encoding immunoglobulin single variable domains may for example be a set, collection or library of nucleic acid sequences encoding a naïve set, collection or library of immunoglobulin sequences; a set, collection or library of nucleic acid sequences encoding a synthetic or semi-synthetic set, collection or library of immunoglobulin sequences; and/or a set, collection or library of nucleic acid sequences encoding a set, collection or library of immunoglobulin sequences that have been subjected to affinity maturation.

In another aspect, the method for generating an amino acid sequence directed against CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) may comprise at least the steps of:

-   a) providing a set, collection or library of nucleic acid sequences     encoding immunoglobulin single variable domains; -   b) screening said set, collection or library of nucleic acid     sequences for nucleic acid sequences that encode an amino acid     sequence that can bind to and/or has affinity for CXCR7 and in     particular human CXCR7 (SEQ ID NO: 1) and that is cross-blocked or     is cross blocking a immunoglobulin single variable domain or     polypeptide of the invention, e.g. SEQ ID NO: 39 to 43 (Table B-2);     and -   c) isolating said nucleic acid sequence, followed by expressing said     amino acid sequence.

The invention also relates to immunoglobulin single variable domains that are obtained by the above methods, or alternatively by a method that comprises the one of the above methods and in addition at least the steps of determining the nucleotide sequence or amino acid sequence of said immunoglobulin sequence; and of expressing or synthesizing said amino acid sequence in a manner known per se, such as by expression in a suitable host cell or host organism or by chemical synthesis.

Also, following the steps above, one or more immunoglobulin single variable domains of the invention may be suitably humanized, camilized or otherwise sequence optimized (e.g. sequence optimized for manufacturability, stability and/or solubility); and/or the amino acid sequence(s) thus obtained may be linked to each other or to one or more other suitable immunoglobulin single variable domains (optionally via one or more suitable linkers) so as to provide a polypeptide of the invention. Also, a nucleic acid sequence encoding an amino acid sequence of the invention may be suitably humanized, camilized or otherwise sequence optimized (e.g. sequence optimized for manufacturability, stability and/or solubility) and suitably expressed; and/or one or more nucleic acid sequences encoding an amino acid sequence of the invention may be linked to each other or to one or more nucleic acid sequences that encode other suitable immunoglobulin single variable domains (optionally via nucleotide sequences that encode one or more suitable linkers), after which the nucleotide sequence thus obtained may be suitably expressed so as to provide a polypeptide of the invention.

The invention further relates to applications and uses of the immunoglobulin single variable domains, compounds, constructs, polypeptides, nucleic acids, host cells, products and compositions described herein, as well as to methods for the diagnosis, prevention and/or treatment for diseases and disorders associated with CXCR7 and in particular human CXCR7 (SEQ ID NO: 1). Some preferred but non-limiting applications and uses will become clear from the further description herein.

The invention also relates to the immunoglobulin single variable domains, compounds, constructs, polypeptides, nucleic acids, host cells, products and compositions described herein for use in therapy.

In particular, the invention also relates to the immunoglobulin single variable domains, compounds, constructs, polypeptides, nucleic acids, host cells, products and compositions described herein for use in therapy of a disease or disorder that can be prevented or treated by administering, to a subject in need thereof, of (a pharmaceutically effective amount of) an amino acid sequence, compound, construct or polypeptide as described herein.

More in particular, the invention relates to the immunoglobulin single variable domains, compounds, constructs, polypeptides, nucleic acids, host cells, products and compositions described herein for use in therapy of cancer.

1.5. Variants of Polypeptides and Immunoglobulin Single Variable Domains of the Invention

Polypeptides of the invention and immunoglobulin single variable domains (that form part of the polypeptides of the invention) may be altered in order to further improve potency or other desired properties.

Generally, an immunoglobulin single variable domain can be defined as a polypeptide with the formula 1 FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4 in which FR1 to FR4 refer to framework regions 1 to 4, respectively, and in which CDR1 to CDR3 refer to the complementarity determining regions 1 to 3, respectively.

Some particularly preferred, but non-limiting combinations of CDR sequences, as well as preferred combinations of CDR sequences and framework sequences, are mentioned in Table B-2 below, which lists the CDR sequences and framework sequences that are present in a number of preferred (but non-limiting) Immunoglobulin single variable domains of the invention. As will be clear to the skilled person, a combination of CDR1, CDR2 and CDR3 sequences that occur in the same clone (i.e. CDR1, CDR2 and CDR3 sequences that are mentioned on the same line in Table B-2) will usually be preferred (although the invention in its broadest sense is not limited thereto, and also comprises other suitable combinations of the CDR sequences mentioned in Table B-2). Also, a combination of CDR sequences and framework sequences that occur in the same clone (i.e. CDR sequences and framework sequences that are mentioned on the same line in Table B-2) will usually be preferred (although the invention in its broadest sense is not limited thereto, and also comprises other suitable combinations of the CDR sequences and framework sequences mentioned in Table B-2, as well as combinations of such CDR sequences and other suitable framework sequences, e.g. as further described herein).

Also, in the immunoglobulin single variable domains of the invention that comprise the combinations of CDR's mentioned in Table B-2, each CDR can be replaced by a CDR chosen from the group consisting of immunoglobulin single variable domains that have at least 80%, preferably at least 90%, more preferably at least 95%, even more preferably at least 99% sequence identity (as defined herein) with the mentioned CDR's; in which:

-   i) any amino acid substitution in such a CDR is preferably, and     compared to the corresponding CDR sequence mentioned in Table B-2, a     conservative amino acid substitution (as defined herein); -   and/or -   ii) any such CDR sequence preferably only contains amino acid     substitutions, and no amino acid deletions or insertions, compared     to the corresponding CDR sequence mentioned in Table B-2; -   and/or -   iii) any such CDR sequence is a CDR that is derived by means of a     technique for affinity maturation known per se, and in particular     starting from the corresponding CDR sequence mentioned in Table B-2.

However, as will be clear to the skilled person, the (combinations of) CDR sequences, as well as (the combinations of) CDR sequences and framework sequences mentioned in Table B-2 will generally be preferred.

Thus, in the immunoglobulin single variable domains of the invention, at least one of the CDR1, CDR2 and CDR3 sequences present is suitably chosen from the group consisting of the CDR1, CDR2 and CDR3 sequences, respectively, listed in Table B-2; or from the group of CDR1, CDR2 and CDR3 sequences, respectively, that have at least 80%, preferably at least 90%, more preferably at least 95%, even more preferably at least 99% “sequence identity” (as defined herein) with at least one of the CDR1, CDR2 and CDR3 sequences, respectively, listed in Table B-2; and/or from the group consisting of the CDR1, CDR2 and CDR3 sequences, respectively, that have 3, 2 or only 1 “amino acid difference(s)” (as defined herein) with at least one of the CDR1, CDR2 and CDR3 sequences, respectively, listed in Table B-2.

In this context, by “suitably chosen” is meant that, as applicable, a CDR1 sequence is chosen from suitable CDR1 sequences (i.e. as defined herein), a CDR2 sequence is chosen from suitable CDR2 sequences (i.e. as defined herein), and a CDR3 sequence is chosen from suitable CDR3 sequence (i.e. as defined herein), respectively. More in particular, the CDR sequences are preferably chosen such that the Nanobodies of the invention bind to CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) with an affinity (suitably measured and/or expressed as a EC50 value, or alternatively as an IC₅₀ value, as further described herein in various in vitro and/or in vivo potency or other assays) that is as defined herein.

In particular, in the immunoglobulin single variable domains of the invention, at least the CDR3 sequence present is suitably chosen from the group consisting of the CDR3 sequences listed in Table B-2 or from the group of CDR3 sequences that have at least 80%, preferably at least 90%, more preferably at least 95%, even more preferably at least 99% sequence identity with at least one of the CDR3 sequences listed in Table B-2; and/or from the group consisting of the CDR3 sequences that have 3, 2 or only 1 amino acid difference(s) with at least one of the CDR3 sequences listed in Table B-2.

Preferably, in the immunoglobulin single variable domains of the invention, at least two of the CDR1, CDR2 and CDR3 sequences present are suitably chosen from the group consisting of the CDR1, CDR2 and CDR3 sequences, respectively, listed in Table B-2 or from the group consisting of CDR1, CDR2 and CDR3 sequences, respectively, that have at least 80%, preferably at least 90%, more preferably at least 95%, even more preferably at least 99% sequence identity with at least one of the CDR1, CDR2 and CDR3 sequences, respectively, listed in Table B-2; and/or from the group consisting of the CDR1, CDR2 and CDR3 sequences, respectively, that have 3, 2 or only 1 “amino acid difference(s)” with at least one of the CDR1, CDR2 and CDR3 sequences, respectively, listed in Table B-2.

In particular, in the immunoglobulin single variable domains of the invention, at least the CDR3 sequence present is suitably chosen from the group consisting of the CDR3 sequences listed in Table B-2 or from the group of CDR3 sequences that have at least 80%, preferably at least 90%, more preferably at least 95%, even more preferably at least 99% sequence identity with at least one of the CDR3 sequences listed in Table B-2, respectively; and at least one of the CDR1 and CDR2 sequences present is suitably chosen from the group consisting of the CDR1 and CDR2 sequences, respectively, listed in Table B-2 or from the group of CDR1 and CDR2 sequences, respectively, that have at least 80%, preferably at least 90%, more preferably at least 95%, even more preferably at least 99% sequence identity with at least one of the CDR1 and CDR2 sequences, respectively, listed in Table B-2; and/or from the group consisting of the CDR1 and CDR2 sequences, respectively, that have 3, 2 or only 1 amino acid difference(s) with at least one of the CDR1 and CDR2 sequences, respectively, listed in Table B-2.

Most preferably, in the immunoglobulin single variable domains of the invention, all three CDR1, CDR2 and CDR3 sequences present are suitably chosen from the group consisting of the CDR1, CDR2 and CDR3 sequences, respectively, listed in Table B-2 or from the group of CDR1, CDR2 and CDR3 sequences, respectively, that have at least 80%, preferably at least 90%, more preferably at least 95%, even more preferably at least 99% sequence identity with at least one of the CDR1, CDR2 and CDR3 sequences, respectively, listed in Table B-2; and/or from the group consisting of the CDR1, CDR2 and CDR3 sequences, respectively, that have 3, 2 or only 1 amino acid difference(s) with at least one of the CDR1, CDR2 and CDR3 sequences, respectively, listed in Table B-2.

Even more preferably, in the immunoglobulin single variable domains of the invention, at least one of the CDR1, CDR2 and CDR3 sequences present is suitably chosen from the group consisting of the CDR1, CDR2 and CDR3 sequences, respectively, listed in Table B-2. Preferably, in this aspect, at least one or preferably both of the other two CDR sequences present are suitably chosen from CDR sequences that have at least 80%, preferably at least 90%, more preferably at least 95%, even more preferably at least 99% sequence identity with at least one of the corresponding CDR sequences, respectively, listed in Table B-2; and/or from the group consisting of the CDR sequences that have 3, 2 or only 1 amino acid difference(s) with at least one of the corresponding sequences, respectively, listed in Table B-2.

In particular, in the immunoglobulin single variable domains of the invention, at least the CDR3 sequence present is suitably chosen from the group consisting of the CDR3 listed in Table B-2. Preferably, in this aspect, at least one and preferably both of the CDR1 and CDR2 sequences present are suitably chosen from the groups of CDR1 and CDR2 sequences, respectively, that have at least 80%, preferably at least 90%, more preferably at least 95%, even more preferably at least 99% sequence identity with the CDR1 and CDR2 sequences, respectively, listed in Table B-2; and/or from the group consisting of the CDR1 and CDR2 sequences, respectively, that have 3, 2 or only 1 amino acid difference(s) with at least one of the CDR1 and CDR2 sequences, respectively, listed in Table B-2.

Even more preferably, in the immunoglobulin single variable domains of the invention, at least two of the CDR1, CDR2 and CDR3 sequences present are suitably chosen from the group consisting of the CDR1, CDR2 and CDR3 sequences, respectively, listed in Table B-2. Preferably, in this aspect, the remaining CDR sequence present is suitably chosen from the group of CDR sequences that have at least 80%, preferably at least 90%, more preferably at least 95%, even more preferably at least 99% sequence identity with at least one of the corresponding CDR sequences listed in Table B-2; and/or from the group consisting of CDR sequences that have 3, 2 or only 1 amino acid difference(s) with at least one of the corresponding sequences listed in Table B-2.

In particular, in the immunoglobulin single variable domains of the invention, at least the CDR3 sequence is suitably chosen from the group consisting of the CDR3 sequences listed in Table B-2, and either the CDR1 sequence or the CDR2 sequence is suitably chosen from the group consisting of the CDR1 and CDR2 sequences, respectively, listed in Table B-2. Preferably, in this aspect, the remaining CDR sequence present is suitably chosen from the group of CDR sequences that have at least 80%, preferably at least 90%, more preferably at least 95%, even more preferably at least 99% sequence identity with at least one of the corresponding CDR sequences listed in Table B-2; and/or from the group consisting of CDR sequences that have 3, 2 or only 1 amino acid difference(s) with the corresponding CDR sequences listed in Table B-2.

Even more preferably, in the immunoglobulin single variable domains of the invention, all three CDR1, CDR2 and CDR3 sequences present are suitably chosen from the group consisting of the CDR1, CDR2 and CDR3 sequences, respectively, listed in Table B-2.

Also, generally, the combinations of CDR's listed in Table B-2 (i.e. those mentioned on the same line in Table B-2) are preferred. Thus, it is generally preferred that, when a CDR in a immunoglobulin single variable domain of the invention is a CDR sequence mentioned in Table B-2 or is suitably chosen from the group of CDR sequences that have at least 80%, preferably at least 90%, more preferably at least 95%, even more preferably at least 99% sequence identity with a CDR sequence listed in Table B-2; and/or from the group consisting of CDR sequences that have 3, 2 or only 1 amino acid difference(s) with a CDR sequence listed in Table B-2, that at least one and preferably both of the other CDR's are suitably chosen from the CDR sequences that belong to the same combination in Table B-2 (i.e. mentioned on the same line in Table B-1) or are suitably chosen from the group of CDR sequences that have at least 80%, preferably at least 90%, more preferably at least 95%, even more preferably at least 99% sequence identity with the CDR sequence(s) belonging to the same combination and/or from the group consisting of CDR sequences that have 3, 2 or only 1 amino acid difference(s) with the CDR sequence(s) belonging to the same combination. The other preferences indicated in the above paragraphs also apply to the combinations of CDR's mentioned in Table B-2.

Thus, by means of non-limiting examples, a polypeptide of the invention can for example comprise a CDR1 sequence that has more than 80% sequence identity with one of the CDR1 sequences mentioned in Table B-2, a CDR2 sequence that has 3, 2 or 1 amino acid difference with one of the CDR2 sequences mentioned in Table B-2 (but belonging to a different combination), and a CDR3 sequence.

Some preferred immunoglobulin single variable domains of the invention may for example comprise: (1) a CDR1 sequence that has more than 80% sequence identity with one of the CDR1 sequences mentioned in Table B-2; a CDR2 sequence that has 3, 2 or 1 amino acid difference with one of the CDR2 sequences mentioned in Table B-2 (but belonging to a different combination); and a CDR3 sequence that has more than 80% sequence identity with one of the CDR3 sequences mentioned in Table B-2 (but belonging to a different combination); or (2) a CDR1 sequence that has more than 80% sequence identity with one of the CDR1 sequences mentioned in Table B-2; a CDR2 sequence, and one of the CDR3 sequences listed in Table B-2; or (3) a CDR1 sequence; a CDR2 sequence that has more than 80% sequence identity with one of the CDR2 sequence listed in Table B-1; and a CDR3 sequence that has 3, 2 or 1 amino acid differences with the CDR3 sequence mentioned in Table B-2 that belongs to the same combination as the CDR2 sequence.

Some particularly preferred immunoglobulin single variable domains of the invention may for example comprise: (1) a CDR1 sequence that has more than 80% sequence identity with one of the CDR1 sequences mentioned in Table B-2; a CDR2 sequence that has 3, 2 or 1 amino acid difference with the CDR2 sequence mentioned in Table B-2 that belongs to the same combination; and a CDR3 sequence that has more than 80% sequence identity with the CDR3 sequence mentioned in Table B-2 that belongs to the same combination; (2) a CDR1 sequence; a CDR2 listed in Table B-2 and a CDR3 sequence listed in Table B-2 (in which the CDR2 sequence and CDR3 sequence may belong to different combinations).

Some even more preferred immunoglobulin single variable domains of the invention may for example comprise: (1) a CDR1 sequence that has more than 80% sequence identity with one of the CDR1 sequences mentioned in Table B-2; the CDR2 sequence listed in Table B-1 that belongs to the same combination; and a CDR3 sequence mentioned in Table B-2 that belongs to a different combination; or (2) a CDR1 sequence mentioned in Table B-2; a CDR2 sequence that has 3, 2 or 1 amino acid differences with the CDR2 sequence mentioned in Table B-2 that belongs to the same combination; and a CDR3 sequence that has more than 80% sequence identity with the CDR3 sequence listed in Table B-2 that belongs to the same or a different combination.

Particularly preferred immunoglobulin single variable domains of the invention may for example comprise a CDR1 sequence mentioned in Table B-2, a CDR2 sequence that has more than 80% sequence identity with the CDR2 sequence mentioned in Table B-2 that belongs to the same combination; and the CDR3 sequence mentioned in Table B-2 that belongs to the same combination.

In the most preferred immunoglobulin single variable domains of the invention, the CDR1, CDR2 and CDR3 sequences present are suitably chosen from one of the combinations of CDR1, CDR2 and CDR3 sequences, respectively, listed in Table B-2.

According to another preferred, but non-limiting aspect of the invention (a) CDR1 has a length of between 1 and 12 amino acid residues, and usually between 2 and 9 amino acid residues, such as 5, 6 or 7 amino acid residues; and/or (b) CDR2 has a length of between 13 and 24 amino acid residues, and usually between 15 and 21 amino acid residues, such as 16 and 17 amino acid residues; and/or (c) CDR3 has a length of between 2 and 35 amino acid residues, and usually between 3 and 30 amino acid residues, such as between 6 and 23 amino acid residues.

In another preferred, but non-limiting aspect, the invention relates to a immunoglobulin single variable domain in which the CDR sequences (as defined herein) have more than 80%, preferably more than 90%, more preferably more than 95%, such as 99% or more sequence identity (as defined herein) with the CDR sequences of at least one of the immunoglobulin single variable domains of SEQ ID NO's: 39 to 43 (see Table B-3).

Another preferred, but non-limiting aspect of the invention relates to humanized variants of the immunoglobulin single variable domains of SEQ ID NO's: 39 to 43 (see Table B-2), that comprise, compared to the corresponding native V_(HH) sequence, at least one humanizing substitution (as defined herein), and in particular at least one humanizing substitution in at least one of its framework sequences (as defined herein).

It will be clear to the skilled person that the immunoglobulin single variable domains that are mentioned herein as “preferred” (or “more preferred”, “even more preferred”, etc.) are also preferred (or more preferred, or even more preferred, etc.) for use in the polypeptides described herein. Thus, polypeptides that comprise or essentially consist of one or more “preferred” immunoglobulin single variable domains of the invention will generally be preferred, and polypeptides that comprise or essentially consist of one or more “more preferred” immunoglobulin single variable domains of the invention will generally be more preferred, etc.

1.6. Nucleotides, Host Cells of the Invention

Another aspect of this invention relates to a nucleic acid that encodes an amino acid sequence of the invention (such as a immunoglobulin single variable domain of the invention) or a polypeptide of the invention comprising the same. Again, as generally described herein for the nucleic acids of the invention, such a nucleic acid may be in the form of a genetic construct, as defined herein. Specific embodiments of this aspect of the invention are provided in Table B-6, SEQ ID NO's: 59 to 63.

In another preferred, but non-limiting aspect, the invention relates to nucleic acid sequences of immunoglobulin single variable domain in which the sequences (as defined herein) have more than 80%, preferably more than 90%, more preferably more than 95%, such as 99% or more sequence identity (as defined herein) with the sequences of at least one of nucleic acid sequence of the immunoglobulin single variable domains of SEQ ID NO's: 59 to 63 (see Table B-6).

In another aspect, the invention relates to nucleic acid sequences that comprise the nucleic acid sequences of immunoglobulin single variable domain in which the sequences (as defined herein) have more than 80%, preferably more than 90%, more preferably more than 95%, such as 99% or more sequence identity (as defined herein) with the sequences of at least one of nucleic acid sequence of the immunoglobulin single variable domains of SEQ ID NO's: 59 to 63 (see Table B-6).

In another aspect, the invention relates to host or host cell that expresses or that is capable of expressing an amino acid sequence (such as a immunoglobulin single variable domain) of the invention and/or a polypeptide of the invention comprising the same; and/or that contains a nucleic acid of the invention. Some preferred but non-limiting examples of such hosts or host cells will become clear from the further description herein.

As will be clear to the skilled person, one particularly useful method for preparing a polypeptide of the invention generally comprises the steps of:

-   i) the expression, in a suitable host cell or host organism (also     referred to herein as a “host of the invention”) or in another     suitable expression system of a nucleic acid that encodes said amino     acid sequence, polypeptide of the invention (also referred to herein     as a “nucleic acid of the invention”), optionally followed by: -   ii) isolating and/or purifying the polypeptide of the invention thus     obtained.

In particular, such a method may comprise the steps of:

-   i) cultivating and/or maintaining a host of the invention under     conditions that are such that said host of the invention expresses     and/or produces at least one polypeptide of the invention;     optionally followed by: -   ii) isolating and/or purifying the polypeptide of the invention thus     obtained.

A nucleic acid of the invention can be in the form of single or double stranded DNA or RNA, and is preferably in the form of double stranded DNA. For example, the nucleotide sequences of the invention may be genomic DNA, cDNA or synthetic DNA (such as DNA with a codon usage that has been specifically adapted for expression in the intended host cell or host organism).

According to one aspect of the invention, the nucleic acid of the invention is in essentially isolated from, as defined herein.

The nucleic acid of the invention may also be in the form of, be present in and/or be part of a vector, such as for example a plasmid, cosmid or YAC, which again may be in essentially isolated form.

The nucleic acids of the invention can be prepared or obtained in a manner known per se, based on the information on the immunoglobulin single variable domains for the polypeptides of the invention given herein, and/or can be isolated from a suitable natural source. To provide analogs, nucleotide sequences encoding naturally occurring V_(HH) domains can for example be subjected to site-directed mutagenesis, so at to provide a nucleic acid of the invention encoding said analog. Also, as will be clear to the skilled person, to prepare a nucleic acid of the invention, also several nucleotide sequences, such as at least one nucleotide sequence encoding a polypeptide of the invention and for example nucleic acids encoding one or more linkers can be linked together in a suitable manner.

Techniques for generating the nucleic acids of the invention will be clear to the skilled person and may for instance include, but are not limited to, automated DNA synthesis; site-directed mutagenesis; combining two or more naturally occurring and/or synthetic sequences (or two or more parts thereof), introduction of mutations that lead to the expression of a truncated expression product; introduction of one or more restriction sites (e.g. to create cassettes and/or regions that may easily be digested and/or ligated using suitable restriction enzymes), and/or the introduction of mutations by means of a PCR reaction using one or more “mismatched” primers, using for example a sequence of a naturally occurring form of CXCR7 and in particular human CXCR7 (SEQ ID NO: 1) as a template. These and other techniques will be clear to the skilled person, and reference is again made to the standard handbooks, such as Sambrook et al. and Ausubel et al., mentioned above, as well as the Examples below.

The nucleic acid of the invention may also be in the form of, be present in and/or be part of a genetic construct, as will be clear to the person skilled in the art and as described on pages 131-134 of WO 08/020079 (incorporated herein by reference). Such genetic constructs generally comprise at least one nucleic acid of the invention that is optionally linked to one or more elements of genetic constructs known per se, such as for example one or more suitable regulatory elements (such as a suitable promoter(s), enhancer(s), terminator(s), etc.) and the further elements of genetic constructs referred to herein. Such genetic constructs comprising at least one nucleic acid of the invention will also be referred to herein as “genetic constructs of the invention”.

The genetic constructs of the invention may be DNA or RNA, and are preferably double-stranded DNA. The genetic constructs of the invention may also be in a form suitable for transformation of the intended host cell or host organism, in a form suitable for integration into the genomic DNA of the intended host cell or in a form suitable for independent replication, maintenance and/or inheritance in the intended host organism. For instance, the genetic constructs of the invention may be in the form of a vector, such as for example a plasmid, cosmid, YAC, a viral vector or transposon. In particular, the vector may be an expression vector, i.e. a vector that can provide for expression in vitro and/or in vivo (e.g. in a suitable host cell, host organism and/or expression system).

In a preferred but non-limiting aspect, a genetic construct of the invention comprises

-   i) at least one nucleic acid of the invention; operably connected to -   ii) one or more regulatory elements, such as a promoter and     optionally a suitable terminator; -   and optionally also -   iii) one or more further elements of genetic constructs known per     se;

in which the terms “operably connected” and “operably linked” have the meaning given on pages 131-134 of WO 08/020079; and in which the “regulatory elements”, “promoter”, “terminator” and “further elements” are as described on pages 131-134 of WO 08/020079; and in which the genetic constructs may further be as described on pages 131-134 of WO 08/020079.

The nucleic acids of the invention and/or the genetic constructs of the invention may be used to transform a host cell or host organism, i.e. for expression and/or production of the polypeptide of the invention. Suitable hosts or host cells will be clear to the skilled person, and may for example be any suitable fungal, prokaryotic or eukaryotic cell or cell line or any suitable fungal, prokaryotic or eukaryotic organism, for example those described on pages 134 and 135 of WO 08/020079.; as well as all other hosts or host cells known per se for the expression and production of antibodies and antibody fragments (including but not limited to (single) domain antibodies and ScFv fragments), which will be clear to the skilled person. Reference is also made to the general background art cited hereinabove, as well as to for example WO 94/29457; WO 96/34103; WO 99/42077.

The immunoglobulin single variable domains, and polypeptides of the invention can for example also be produced in the milk of transgenic mammals, for example in the milk of rabbits, cows, goats or sheep (see for example U.S. Pat. No. 6,741,957, U.S. Pat. No. 6,304,489 and U.S. Pat. No. 6,849,992 for general techniques for introducing transgenes into mammals), in plants or parts of plants including but not limited to their leaves, flowers, fruits, seed, roots or turbers (for example in tobacco, maize, soybean or alfalfa) or in for example pupae of the silkworm Bombix mori.

Furthermore, the immunoglobulin single variable domains, and polypeptides of the invention can also be expressed and/or produced in cell-free expression systems, and suitable examples of such systems will be clear to the skilled person. Some preferred, but non-limiting examples include expression in the wheat germ system; in rabbit reticulocyte lysates; or in the E. coli Zubay system.

As mentioned above, one of the advantages of the use of immunoglobulin single variable domains is that the polypeptides based thereon can be prepared through expression in a suitable bacterial system, and suitable bacterial expression systems, vectors, host cells, regulatory elements, etc., will be clear to the skilled person, for example from the references cited above. It should however be noted that the invention in its broadest sense is not limited to expression in bacterial systems.

Preferably, in the invention, an (in vivo or in vitro) expression system, such as a bacterial expression system, is used that provides the polypeptides of the invention in a form that is suitable for pharmaceutical use, and such expression systems will again be clear to the skilled person. As also will be clear to the skilled person, polypeptides of the invention suitable for pharmaceutical use can be prepared using techniques for peptide synthesis.

For production on industrial scale, preferred heterologous hosts for the (industrial) production of immunoglobulin single variable domains or immunoglobulin single variable domain-containing protein therapeutics include strains of E. coli, Pichia pastoris, S. cerevisiae that are suitable for large scale expression/production/fermentation, and in particular for large scale pharmaceutical (i.e. GMP grade) expression/production/fermentation. Suitable examples of such strains will be clear to the skilled person. Such strains and production/expression systems are also made available by companies such as Richter Helm (Hamburg, Germany) or CMC Biologics (Soeborg, Denmark).

Alternatively, mammalian cell lines, in particular Chinese hamster ovary (CHO) cells, can be used for large scale expression/production/fermentation, and in particular for large scale pharmaceutical expression/production/fermentation. Again, such expression/production systems are also made available by some of the companies mentioned above.

The choice of the specific expression system would depend in part on the requirement for certain post-translational modifications, more specifically glycosylation. The production of a immunoglobulin single variable domain-containing recombinant protein for which glycosylation is desired or required would necessitate the use of mammalian expression hosts that have the ability to glycosylate the expressed protein. In this respect, it will be clear to the skilled person that the glycosylation pattern obtained (i.e. the kind, number and position of residues attached) will depend on the cell or cell line that is used for the expression. Preferably, either a human cell or cell line is used (i.e. leading to a protein that essentially has a human glycosylation pattern) or another mammalian cell line is used that can provide a glycosylation pattern that is essentially and/or functionally the same as human glycosylation or at least mimics human glycosylation. Generally, prokaryotic hosts such as E. coli do not have the ability to glycosylate proteins, and the use of lower eukaryotes such as yeast usually leads to a glycosylation pattern that differs from human glycosylation. Nevertheless, it should be understood that all the foregoing host cells and expression systems can be used in the invention, depending on the desired polypeptide to be obtained.

Thus, according to one non-limiting aspect of the invention, the polypeptide of the invention is glycosylated. According to another non-limiting aspect of the invention, the polypeptide of the invention is non-glycosylated.

According to one preferred, but non-limiting aspect of the invention, the polypeptide of the invention is produced in a bacterial cell, in particular a bacterial cell suitable for large scale pharmaceutical production, such as cells of the strains mentioned above.

According to another preferred, but non-limiting aspect of the invention, the polypeptide of the invention is produced in a yeast cell, in particular a yeast cell suitable for large scale pharmaceutical production, such as cells of the species mentioned above.

According to yet another preferred, but non-limiting aspect of the invention, the polypeptide of the invention is produced in a mammalian cell, in particular in a human cell or in a cell of a human cell line, and more in particular in a human cell or in a cell of a human cell line that is suitable for large scale pharmaceutical production, such as the cell lines mentioned hereinabove.

As further described on pages 138 and 139 of WO 08/020079, when expression in a host cell is used to produce the immunoglobulin single variable domains, and the polypeptides of the invention, the immunoglobulin single variable domains, and polypeptides of the invention can be produced either intracellullarly (e.g. in the cytosol, in the periplasma or in inclusion bodies) and then isolated from the host cells and optionally further purified; or can be produced extracellularly (e.g. in the medium in which the host cells are cultured) and then isolated from the culture medium and optionally further purified. Thus, according to one non-limiting aspect of the invention, the polypeptide of the invention is an amino acid sequence, polypeptide that has been produced intracellularly and that has been isolated from the host cell, and in particular from a bacterial cell or from an inclusion body in a bacterial cell. According to another non-limiting aspect of the invention, the amino acid sequence, or polypeptide of the invention is an amino acid sequence, or polypeptide that has been produced extracellularly, and that has been isolated from the medium in which the host cell is cultivated.

Some preferred, but non-limiting promoters for use with these host cells include those mentioned on pages 139 and 140 of WO 08/020079.

Some preferred, but non-limiting secretory sequences for use with these host cells include those mentioned on page 140 of WO 08/020079.

Suitable techniques for transforming a host or host cell of the invention will be clear to the skilled person and may depend on the intended host cell/host organism and the genetic construct to be used. Reference is again made to the handbooks and patent applications mentioned above.

After transformation, a step for detecting and selecting those host cells or host organisms that have been successfully transformed with the nucleotide sequence/genetic construct of the invention may be performed. This may for instance be a selection step based on a selectable marker present in the genetic construct of the invention or a step involving the detection of the amino acid sequence of the invention, e.g. using specific antibodies.

The transformed host cell (which may be in the form or a stable cell line) or host organisms (which may be in the form of a stable mutant line or strain) form further aspects of the present invention.

Preferably, these host cells or host organisms are such that they express, or are (at least) capable of expressing (e.g. under suitable conditions), a polypeptide of the invention (and in case of a host organism: in at least one cell, part, tissue or organ thereof). The invention also includes further generations, progeny and/or offspring of the host cell or host organism of the invention, that may for instance be obtained by cell division or by sexual or asexual reproduction.

To produce/obtain expression of the immunoglobulin single variable domains of the invention, the transformed host cell or transformed host organism may generally be kept, maintained and/or cultured under conditions such that the (desired) amino acid sequence, or polypeptide of the invention is expressed/produced. Suitable conditions will be clear to the skilled person and will usually depend upon the host cell/host organism used, as well as on the regulatory elements that control the expression of the (relevant) nucleotide sequence of the invention. Again, reference is made to the handbooks and patent applications mentioned above in the paragraphs on the genetic constructs of the invention.

Generally, suitable conditions may include the use of a suitable medium, the presence of a suitable source of food and/or suitable nutrients, the use of a suitable temperature, and optionally the presence of a suitable inducing factor or compound (e.g. when the nucleotide sequences of the invention are under the control of an inducible promoter); all of which may be selected by the skilled person. Again, under such conditions, the immunoglobulin single variable domains of the invention may be expressed in a constitutive manner, in a transient manner, or only when suitably induced.

It will also be clear to the skilled person that the amino acid sequence, or polypeptide of the invention may (first) be generated in an immature form (as mentioned above), which may then be subjected to post-translational modification, depending on the host cell/host organism used. Also, the amino acid sequence, or polypeptide of the invention may be glycosylated, again depending on the host cell/host organism used.

The amino acid sequence, or polypeptide of the invention may then be isolated from the host cell/host organism and/or from the medium in which said host cell or host organism was cultivated, using protein isolation and/or purification techniques known per se, such as (preparative) chromatography and/or electrophoresis techniques, differential precipitation techniques, affinity techniques (e.g. using a specific, cleavable amino acid sequence fused with the amino acid sequence, or polypeptide of the invention) and/or preparative immunological techniques (i.e. using antibodies against the amino acid sequence to be isolated).

The entire contents of all of the references (including literature references, issued patents, published patent applications, and co-pending patent applications) cited throughout this application are hereby expressly incorporated by reference, in particular for the teaching that is referenced herein.

The invention will now be further described by means of the following non-limiting preferred aspects, figures and examples:

Preferred Non-Limiting Aspects:

-   Aspect A-1: An immunoglobulin single variable domain that is     directed against and/or that can specifically bind to CXCR7 and in     particular human CXCR7 (SEQ ID NO: 1). -   Aspect A-2: An immunoglobulin single variable domain according to     aspect A-1, that is in essentially isolated form. -   Aspect A-3: An immunoglobulin single variable domain according to     aspect A-1 or A-2, for administration to a subject, wherein said     immunoglobulin single variable domain does not naturally occur in     said subject. -   Aspect A-4: An immunoglobulin single variable domain that can     specifically bind to CXCR7 and in particular human CXCR7 (SEQ ID     NO: 1) with a dissociation constant (K_(D)) of 10⁻⁵ to 10⁻¹²     moles/liter or less, and preferably 10⁻⁷ to 10⁻¹² moles/liter or     less and more preferably 10⁻⁸ to 10⁻¹² moles/liter. Such an     immunoglobulin single variable domain may in particular be an     immunoglobulin single variable domain according to any of the     preceding aspects. -   Aspect A-5: An immunoglobulin single variable domain that can     specifically bind to CXCR7 and in particular human CXCR7 (SEQ ID     NO: 1) with a rate of association (k_(on)-rate) of between 10²     M⁻¹s⁻¹ to about 10⁷ M⁻¹s⁻¹, preferably between 10³ M⁻¹s⁻¹ and 10⁷     M⁻¹s⁻¹, more preferably between 10⁴ M⁻¹s⁻¹ and 10⁷ M⁻¹s⁻¹, such as     between 10⁵ M⁻¹s⁻¹ and 10⁷ M⁻¹s⁻¹. Such an immunoglobulin single     variable domain may in particular be an immunoglobulin single     variable domain according to any of the preceding aspects. -   Aspect A-6: An immunoglobulin single variable domain that can     specifically bind to CXCR7 and in particular human CXCR7 (SEQ ID     NO: 1) with a rate of dissociation (k_(off) rate) between 1 s⁻¹ and     10⁻⁶ s⁻¹, preferably between 10⁻² s⁻¹ and 10⁻⁶ s⁻¹, more preferably     between 10⁻³ s⁻¹ and 10⁻⁶ s⁻¹, such as between 10⁴ s⁻¹ and 10⁻⁶ s⁻¹.     Such an immunoglobulin single variable domain may in particular be     an immunoglobulin single variable domain according to any of the     preceding aspects. -   Aspect A-7: An immunoglobulin single variable domain that can     specifically bind to CXCR7 and in particular human CXCR7 (SEQ ID     NO: 1) with an affinity less than 500 nM, preferably less than 200     nM, more preferably less than 10 nM, such as less than 500 pM. Such     an immunoglobulin single variable domain may in particular be an     immunoglobulin single variable domain according to any of the     preceding aspects. -   Aspect A-8: An immunoglobulin single variable domain that can     specifically displace SDF-1 and/or I-TAC (CXCL11 and/or CXCL12) on     CXCR7 and in particular on human CXCR7 (SEQ ID NO: 1) with an     average Ki of less than 500 nM, preferably less than 200 nM, more     preferably less than 10 nM, such as less than 1 nM and an average     SDF-1 and/or I-TAC displacement of 50% or more, more preferably of     75% or more, even more preferably of 80% or more. Such an average Ki     and/or average displacement value may be determined e.g. in an assay     as described in example 9 or 10. -   Aspect A-9: An immunoglobulin single variable domain that can     specifically displace SDF-1 and/or I-TAC (CXCL11 and/or CXCL12) on     CXCR7 and in particular on human CXCR7 (SEQ ID NO: 1) with an     average Ki of less than 20 nM and an average SDF-1 and/or I-TAC     displacement of 70% or more. Such an average Ki and/or average     displacement value may be determined e.g. in an assay as described     in example 9 or 10. -   Aspect A-10: An immunoglobulin single variable domain according to     any of the preceding aspects, that essentially consists of 4     framework regions (FR1 to FR4 respectively) and 3 complementarity     determining regions (CDR1 to CDR3 respectively). -   Aspect A-11: An immunoglobulin single variable domain according to     any of the preceding aspects, that is an immunoglobulin sequence. -   Aspect A-12: An immunoglobulin single variable domain according to     any of the preceding aspects, that is a naturally occurring     immunoglobulin sequence (from any suitable species) or a synthetic     or semi-synthetic immunoglobulin sequence. -   Aspect A-13: An immunoglobulin single variable domain according to     any of the preceding aspects that is a humanized immunoglobulin     sequence, a camelized immunoglobulin sequence or an immunoglobulin     sequence that has been obtained by techniques such as affinity     maturation. -   Aspect A-14: An immunoglobulin single variable domain according to     any of the preceding aspects, that essentially consists of a light     chain variable domain sequence (e.g. a VL-sequence); or of a heavy     chain variable domain sequence (e.g. a VH-sequence). -   Aspect A-15: An immunoglobulin single variable domain according to     any of the preceding aspects, that essentially consists of a heavy     chain variable domain sequence that is derived from a conventional     four-chain antibody or that essentially consist of a heavy chain     variable domain sequence that is derived from heavy chain antibody. -   Aspect A-16: An immunoglobulin single variable domain according to     any of the preceding aspects, that essentially consists of a domain     antibody (or an immunoglobulin single variable domain that is     suitable for use as a domain antibody), of a single domain antibody     (or an immunoglobulin single variable domain that is suitable for     use as a single domain antibody), of a “dAb” (or an immunoglobulin     single variable domain that is suitable for use as a dAb) or of a     Nanobody (including but not limited to a VHH sequence). -   Aspect A-17: An immunoglobulin single variable domain according to     any of the preceding aspects, that essentially consists of a     Nanobody. -   Aspect A-18: An immunoglobulin single variable domain according to     any of the preceding aspects, that essentially consists of a     Nanobody that     -   i) has at least 80% amino acid identity with at least one of the         immunoglobulin single variable domains of SEQ ID NO's: 1 to 22         of WO 2009/138519, in which for the purposes of determining the         degree of amino acid identity, the amino acid residues that form         the CDR sequences are disregarded;     -   and in which:     -   ii) preferably one or more of the amino acid residues at         positions 11, 37, 44, 45, 47, 83, 84, 103, 104 and 108 according         to the Kabat numbering are chosen from the Hallmark residues         mentioned in Table A-1. -   Aspect A-19: An immunoglobulin single variable domain according to     any of the preceding aspects, that essentially consists of an     immunoglobulin single variable domain that     -   i) has at least 80% amino acid identity with at least one of the         immunoglobulin single variable domains of SEQ ID NO's: 39 to 43,         in which for the purposes of determining the degree of amino         acid identity, the amino acid residues that form the CDR         sequences are disregarded;     -   and in which:     -   ii) preferably one or more of the amino acid residues at         positions 11, 37, 44, 45, 47, 83, 84, 103, 104 and 108 according         to the Kabat numbering are chosen from the Hallmark residues         mentioned in Table A-1. -   Aspect A-20: An immunoglobulin single variable domain according to     any of the preceding aspects, that essentially consists of a     polypeptide that comprises of     -   i) A first immunoglobulin single variable domain that has at         least 80% amino acid identity with an immunoglobulin single         variable domain selected from the group of immunoglobulin single         variable domain having SEQ ID NO's: 39 to 43, in which for the         purposes of determining the degree of amino acid identity, the         amino acid residues that form the CDR sequences are disregarded;         and that comprises of     -   ii) A second immunoglobulin single variable domain that has at         least 80% amino acid identity with the immunoglobulin single         variable domain having SEQ ID NO: 2, in which for the purposes         of determining the degree of amino acid identity, the amino acid         residues that form the CDR sequences are disregarded; and         optionally also comprises     -   iii) A linker. -   Aspect A-21: An immunoglobulin single variable domain according to     any of the preceding aspects, that essentially consists of a     humanized or otherwise sequence optimized immunoglobulin single     variable domain. -   Aspect A-22: An immunoglobulin single variable domain according to     any of the preceding aspects, that in addition to the at least one     binding site for binding against CXCR7 and in particular human CXCR7     (SEQ ID NO: 1), contains one or more further binding sites for     binding against other antigens, proteins or targets.     Cdr-Based Aspects -   Aspect B-1: An immunoglobulin single variable domain that is     directed against and/or that can specifically bind CXCR7 and in     particular human CXCR7 (SEQ ID NO: 1), and that comprises one or     more (preferably one) stretches of amino acid residues chosen from     the group consisting of:     -   a) the immunoglobulin single variable domains of SEQ ID NO's: 9         to 13;     -   b) immunoglobulin single variable domains that have at least 80%         amino acid identity with at least one of the immunoglobulin         single variable domains of SEQ ID NO's: 9 to 13;     -   c) immunoglobulin single variable domains that have 3, 2, or 1         amino acid difference with at least one of the immunoglobulin         single variable domains of SEQ ID NO's: 9 to 13;     -   d) the immunoglobulin single variable domains of SEQ ID NO's: 19         to 23;     -   e) immunoglobulin single variable domains that have at least 80%         amino acid identity with at least one of the immunoglobulin         single variable domains of SEQ ID NO's: 19 to 23;     -   f) immunoglobulin single variable domains that have 3, 2, or 1         amino acid difference with at least one of the immunoglobulin         single variable domains of SEQ ID NO's: 19 to 23;     -   g) the immunoglobulin single variable domains of SEQ ID NO's: 29         to 33;     -   h) immunoglobulin single variable domains that have at least 80%         amino acid identity with at least one of the immunoglobulin         single variable domains of SEQ ID NO's: 29 to 33;     -   i) immunoglobulin single variable domains that have 3, 2, or 1         amino acid difference with at least one of the immunoglobulin         single variable domains of SEQ ID NO's: 29 to 33;     -   or any suitable combination thereof.     -   Such an immunoglobulin single variable domain may in particular         be VHH or sequence optimized VHH such as humanized, stabilized         and/or solubilized VHH. -   Aspect B-2: An immunoglobulin single variable domain according to     aspect B-1, in which at least one of said stretches of amino acid     residues forms part of the antigen binding site for binding against     CXCR7 and in particular human CXCR7 (SEQ ID NO: 1). -   Aspect B-3: An immunoglobulin single variable domain sequence that     is directed against and/or that can specifically bind CXCR7 and in     particular human CXCR7 (SEQ ID NO: 1) and that comprises two or more     stretches of amino acid residues chosen from the group consisting     of:     -   a) the immunoglobulin single variable domains of SEQ ID NO's: 9         to 13;     -   b) immunoglobulin single variable domains that have at least 80%         amino acid identity with at least one of the immunoglobulin         single variable domains of SEQ ID NO's: 9 to 13;     -   c) immunoglobulin single variable domains that have 3, 2, or 1         amino acid difference with at least one of the immunoglobulin         single variable domains of SEQ ID NO's: 9 to 13;     -   d) the immunoglobulin single variable domains of SEQ ID NO's: 19         to 23;     -   e) immunoglobulin single variable domains that have at least 80%         amino acid identity with at least one of the immunoglobulin         single variable domains of SEQ ID NO's: 19 to 23;     -   f) immunoglobulin single variable domains that have 3, 2, or 1         amino acid difference with at least one of the immunoglobulin         single variable domains of SEQ ID NO's: 19 to 23;     -   g) the immunoglobulin single variable domains of SEQ ID NO's: 29         to 33;     -   h) immunoglobulin single variable domains that have at least 80%         amino acid identity with at least one of the immunoglobulin         single variable domains of SEQ ID NO's: 29 to 33;     -   i) immunoglobulin single variable domains that have 3, 2, or 1         amino acid difference with at least one of the immunoglobulin         single variable domains of SEQ ID NO's: 29 to 33;     -   such that (i) when the first stretch of amino acid residues         corresponds to one of the immunoglobulin single variable domains         according to a), b) or c), the second stretch of amino acid         residues corresponds to one of the immunoglobulin single         variable domains according to d), e), f), g), h) or i); (ii)         when the first stretch of amino acid residues corresponds to one         of the immunoglobulin single variable domains according to         d), e) or f), the second stretch of amino acid residues         corresponds to one of the immunoglobulin single variable domains         according to a), b), c), g), h) or i); or (iii) when the first         stretch of amino acid residues corresponds to one of the         immunoglobulin single variable domains according to g), h) or         i), the second stretch of amino acid residues corresponds to one         of the immunoglobulin single variable domains according to a),         b), c), d), e) or f).     -   Such an immunoglobulin single variable domain may in particular         be VHH or sequence optimized VHH such as humanized, stabilized         and/or solubilized VHH. -   Aspect B-4: An immunoglobulin single variable domain according to     aspect B-3, in which the at least two stretches of amino acid     residues forms part of the antigen binding site for binding against     CXCR7 and in particular human CXCR7 (SEQ ID NO: 1). -   Aspect B-5: An immunoglobulin single variable domain sequence that     is directed against and/or that can specifically bind CXCR7 and in     particular human CXCR7 (SEQ ID NO: 1) and that comprises three or     more stretches of amino acid residues, in which the first stretch of     amino acid residues is chosen from the group consisting of:     -   a) the immunoglobulin single variable domains of SEQ ID NO's: 9         to 13;     -   b) immunoglobulin single variable domains that have at least 80%         amino acid identity with at least one of the immunoglobulin         single variable domains of SEQ ID NO's: 9 to 13;     -   c) immunoglobulin single variable domains that have 3, 2, or 1         amino acid difference with at least one of the immunoglobulin         single variable domains of SEQ ID NO's: 9 to 13;     -   the second stretch of amino acid residues is chosen from the         group consisting of:     -   d) the immunoglobulin single variable domain of SEQ ID NO's: 19         to 23;     -   e) immunoglobulin single variable domains that have at least 80%         amino acid identity with at least one of the immunoglobulin         single variable domains of SEQ ID NO's: 19 to 23;     -   f) immunoglobulin single variable domains that have 3, 2, or 1         amino acid difference with at least one of the immunoglobulin         single variable domains of SEQ ID NO's: 19 to 23;     -   and the third stretch of amino acid residues is chosen from the         group consisting of:     -   g) the immunoglobulin single variable domains of SEQ ID NO's: 29         to 33;     -   h) immunoglobulin single variable domains that have at least 80%         amino acid identity with at least one of the immunoglobulin         single variable domains of SEQ ID NO's: 29 to 33;     -   i) immunoglobulin single variable domains that have 3, 2, or 1         amino acid difference with at least one of the immunoglobulin         single variable domains of SEQ ID NO's: 29 to 33.     -   Such an immunoglobulin single variable domain may in particular         be VHH or sequence optimized VHH such as humanized, stabilized         and/or solubilized VHH. -   Aspect B-6: An immunoglobulin single variable domain according to     aspect B-5, in which the at least three stretches of amino acid     residues forms part of the antigen binding site for binding against     CXCR7 and in particular human CXCR7 (SEQ ID NO: 1). -   Aspect B-7: An immunoglobulin single variable domain that is     directed against and/or that can specifically bind CXCR7 and in     particular human CXCR7 (SEQ ID NO: 1) in which the CDR sequences of     said immunoglobulin single variable domain have at least 70% amino     acid identity, preferably at least 80% amino acid identity, more     preferably at least 90% amino acid identity, such as 95% amino acid     identity or more or even essentially 100% amino acid identity with     the CDR sequences of at least one of the immunoglobulin single     variable domains of SEQ ID NO's: 39 to 43.     -   Such an immunoglobulin single variable domain may in particular         be VHH or sequence optimized VHH such as humanized, stabilized         and/or solubilized VHH. -   Aspect C-1: An immunoglobulin single variable domain or polypeptide     that is directed against CXCR7 and in particular human CXCR7 (SEQ ID     NO: 1) and that cross-blocks the binding of at least one of the     immunoglobulin single variable domains of SEQ ID NO's: 39 to 43 or     polypeptides of SEQ ID NO's: 44 to 48 to CXCR7 and in particular     human CXCR7 (SEQ ID NO: 1). Such an immunoglobulin single variable     domain may in particular be an immunoglobulin single variable domain     according to any of the aspects A-1 to A-22 and/or according to     aspects B-1 to B-7. Also, preferably, such an immunoglobulin single     variable domain is able to specifically bind to CXCR7 and in     particular human CXCR7 (SEQ ID NO: 1). -   Aspect C-2: An immunoglobulin single variable domain or polypeptide     that is directed against CXCR7 and in particular human CXCR7 (SEQ ID     NO: 1) and that is cross-blocked from binding to CXCR7 and in     particular human CXCR7 (SEQ ID NO: 1) by at least one of the     immunoglobulin single variable domains of SEQ ID NO's: 39 to 43 or     polypeptides of SEQ ID NO's: 44 to 48. Such an immunoglobulin single     variable domain may in particular be an immunoglobulin single     variable domain according to any of the aspects A-1 to A-22 and/or     according to aspects B-1 to B-7. Also, preferably, such an     immunoglobulin single variable domain is able to specifically bind     to CXCR7 and in particular human CXCR7 (SEQ ID NO: 1). -   Aspect C-3: An immunoglobulin single variable domain or polypeptide     according to any of aspects C-1 or C-2, wherein the ability of said     immunoglobulin single variable domain to cross-block or to be     cross-blocked is detected in a displacement assay (e.g. as described     in examples 9 and/or 10 below). -   Aspect C-4: An immunoglobulin single variable domain or polypeptide     according to any of aspects C-1 to C-3 wherein the ability of said     immunoglobulin single variable domain to cross-block or to be     cross-blocked is detected in an ELISA assay. -   Aspect D-1: An immunoglobulin single variable domain according to     any of aspects B-1 to B-7 or C-1 to C-7, that is in essentially     isolated form. -   Aspect D-2: An immunoglobulin single variable domain according to     any of aspects B-1 to B-7, C-1 to C-7, and/or D1 for administration     to a subject, wherein said immunoglobulin single variable domain     does not naturally occur in said subject. -   Aspect D-3: An immunoglobulin single variable domain according to     any of aspects B-1 to B-7, C-1 to C-7, and/or D1 to D-2 that can     specifically bind to CXCR7 and in particular human CXCR7 (SEQ ID     NO: 1) with a dissociation constant (K_(D)) of 10⁻⁵ to 10⁻¹²     moles/liter or less, and preferably 10⁻⁷ to 10⁻¹² moles/liter or     less and more preferably 10⁻⁸ to 10⁻¹² moles/liter. -   Aspect D-4: An immunoglobulin single variable domain according to     any of aspects B-1 to B-7, C-1 to C-7, and/or D-1 to D-3 that can     specifically bind to CXCR7 and in particular human CXCR7 (SEQ ID     NO: 1) with a rate of association (k_(on)-rate) of between 10²     M⁻¹s⁻¹ to about 10⁷ M⁻¹s⁻¹, preferably between 10³ M⁻¹s⁻¹ and 10⁷     M⁻¹s⁻¹, more preferably between 10⁴ M⁻¹s⁻¹ and 10⁷ M⁻¹s⁻¹, such as     between 10⁵ M⁻¹s⁻¹ and 10⁷ M⁻¹s⁻¹. -   Aspect D-5: An immunoglobulin single variable domain according to     any of aspects B-1 to B-7, C-1 to C-7, and/or D-1 to D-4 that can     specifically bind to CXCR7 and in particular human CXCR7 (SEQ ID     NO: 1) with a rate of dissociation (k_(off) rate) between 1 s⁻¹ and     10⁻⁶ s⁻¹ preferably between 10⁻² s⁻¹ and 10⁻⁶ s⁻¹, more preferably     between 10⁻³ s⁻¹ and 10⁻⁶ s⁻¹, such as between 10⁻⁴ s⁻¹ and 10⁻⁶     s⁻¹. -   Aspect D-6: An immunoglobulin single variable domain according to     any of aspects B-1 to B-7, C-1 to C-7, and/or D-1 to D-5 that can     specifically bind to CXCR7 and in particular human CXCR7 (SEQ ID     NO: 1) with an affinity less than 500 nM, preferably less than 200     nM, more preferably less than 10 nM, such as less than 500 pM.     -   The immunoglobulin single variable domains according to aspects         D-1 to D-6 may in particular be an immunoglobulin single         variable domain according to any of the aspects A-1 to A-22. -   Aspect E-1: An immunoglobulin single variable domain according to     any of aspects B-1 to B-7, C-1 to C-7 and/or D1 to D-6, that is a     naturally occurring immunoglobulin single variable domain (from any     suitable species) or a synthetic or semi-synthetic immunoglobulin     single variable domain. -   Aspect E-2: An immunoglobulin single variable domain according to     any of aspects B-1 to B-7, C-1 to C-7, D1 to D-6, and/or E-1 that is     sequence optimized -   Aspect E-3: An immunoglobulin single variable domain according to     any of aspects B-1 to B-7, C-1 to C-7, D1 to D-6, and/or D-1 or D-2,     that is stabilized. -   Aspect E-4: An immunoglobulin single variable domain according to     any of aspects B-1 to B-7, C-1 to C-7, D1 to D-6, and/or E-1 to E-3,     that is a naturally occurring immunoglobulin sequence (from any     suitable species) or a synthetic or semi-synthetic immunoglobulin     sequence. -   Aspect E-5: An immunoglobulin single variable domain according to     any of aspects B-1 to B-7, C-1 to C-7, D1 to D-6, and/or E-1 to E-4     that is a humanized immunoglobulin sequence, a camelized     immunoglobulin sequence or an immunoglobulin sequence that has been     obtained by techniques such as affinity maturation. -   Aspect E-6: An immunoglobulin single variable domain according to     any of aspects B-1 to B-7, C-1 to C-7, D1 to D-6, and/or E-1 to E-5     that essentially consists of a light chain variable domain sequence     (e.g. a V_(L)-sequence); or of a heavy chain variable domain     sequence (e.g. a V_(H)-sequence). -   Aspect E-7: An immunoglobulin single variable domain according to     any of aspects B-1 to B-7, C-1 to C-7, D1 to D-6, and/or E-1 to E-6,     that essentially consists of a heavy chain variable domain sequence     that is derived from a conventional four-chain antibody or that     essentially consist of a heavy chain variable domain sequence that     is derived from heavy chain antibody. -   Aspect E-8: An immunoglobulin single variable domain according to     any of aspects B-1 to B-7, C-1 to C-7, D1 to D-6, and/or E-1 to E-7,     that essentially consists of a domain antibody (or an immunoglobulin     single variable domain that is suitable for use as a domain     antibody), of a single domain antibody (or an immunoglobulin single     variable domain that is suitable for use as a single domain     antibody), of a “dAb” (or an immunoglobulin single variable domain     that is suitable for use as a dAb) or of a Nanobody (including but     not limited to a V_(HH) sequence). -   Aspect E-9: An immunoglobulin single variable domain according to     any of aspects B-1 to B-7, C-1 to C-7, D1 to D-6, and/or E-1 to E-8     that essentially consists of a Nanobody. -   Aspect E-10: An immunoglobulin single variable domain according to     any of aspects B-1 to B-7, C-1 to C-7, D1 to D-6, and/or E-1 to E-9     that essentially consists of a immunoglobulin single variable domain     that     -   i) has at least 80% amino acid identity with at least one of the         immunoglobulin single variable domains described herein, in         which for the purposes of determining the degree of amino acid         identity, the amino acid residues that form the CDR sequences         are disregarded;     -   and in which:     -   ii) preferably one or more of the amino acid residues at         positions 11, 37, 44, 45, 47, 83, 84, 103, 104 and 108 according         to the Kabat numbering are chosen from the Hallmark residues         mentioned in Table B-2. -   Aspect E-11: An immunoglobulin single variable domain according to     any of aspects B-1 to B-7, C-1 to C-7, D1 to D-6, and/or E-1 to     E-10, that essentially consists of an immunoglobulin single variable     domain that     -   i) has at least 80% amino acid identity with at least one of the         An immunoglobulin single variable domains of SEQ ID NO's: 39 to         43, in which for the purposes of determining the degree of amino         acid identity, the amino acid residues that form the CDR         sequences are disregarded;     -   and in which:     -   ii) preferably one or more of the amino acid residues at         positions 11, 37, 44, 45, 47, 83, 84, 103, 104 and 108 according         to the Kabat numbering are chosen from the Hallmark residues         mentioned in Table B-2. -   Aspect E-12: An immunoglobulin single variable domain according to     any of aspects B-1 to B-7, C-1 to C-7, D1 to D-6, and/or E-1 to E-11     that essentially consists of a humanized immunoglobulin single     variable domain. -   Aspect E-13: An immunoglobulin single variable domain according to     any of the aspects B-1 to B-7, C-1 to C-7, D1 to D-6, and/or E-1 to     E-11, that in addition to the at least one binding site for binding     formed by the CDR sequences, contains one or more further binding     sites for binding against other antigens, proteins or targets.     -   The immunoglobulin single variable domains according to aspects         E-1 to E-13 may in particular be an immunoglobulin single         variable domain according to any of the aspects A-1 to A-22.         Polypeptides -   Aspect K-1: Polypeptide that comprises of one or more (preferably     one) immunoglobulin single variable domains according to any of     aspects A-1 to A-22, B-1 to B-7, C-1 to C-4, D-1 to D-6, and/or E-1     to E-13, and optionally further comprises one or more peptidic     linkers. -   Aspect K-2: Polypeptide according to aspect K-1, which additionally     comprises one or more (preferably one) immunoglobulin single     variable domain directed against serum albumin -   Aspect K-3: Polypeptide according to any of aspects K-1 or K-2, in     which said immunoglobulin single variable domain directed against     serum albumin is directed against human serum albumin -   Aspect K-4: Polypeptide according to any of aspects K-1 to K-3, in     which said one or more immunoglobulin single variable domain     directed against serum albumin is an immunoglobulin single variable     domain with SEQ ID NO: 2. -   Aspect K-5: Polypeptide that comprises of one or more (preferably     one) immunoglobulin single variable domains according to any of     aspects A-1 to A-22, B-1 to B-7, C-1 to C-4, D-1 to D-6, and/or E-1     to E-13, one or more cytotoxic payloads, and optionally further     comprises one or more peptidic linkers. -   Aspect K-6: Polypeptide that comprises or essentially consists of     one or more (preferably one) immunoglobulin single variable domains     according to any of aspects A-1 to A-22, B-1 to B-7, C-1 to C-4, D-1     to D-6, and/or E-1 to E-13, one or more (and preferably one)     immunoglobulin single variable domains (preferably Nanobody)     directed against CXCR4 and optionally further comprises one or more     peptidic linkers. -   Aspect K-7: Polypeptide that comprises or essentially consists of at     least one (preferably one) immunoglobulin single variable domain     (preferably Nanobody) directed against (human) CXCR7 and at least     one (cyto)toxic group, moiety or payload (optionally linked     chemically or via one or more suitable linkers or spacers). -   Aspect K-8: Polypeptide that comprises or essentially consists of at     least one (preferably one) immunoglobulin single variable domain     (preferably Nanobody) directed against (human) CXCR7, at least one     (preferably one) immunoglobulin single variable domain (preferably     Nanobody) directed against (human) CXCR4 and at least one     (cyto)toxic group, moiety or payload (optionally linked chemically     or via one or more suitable linkers or spacers). -   Aspect K-9: Polypeptide that comprises or essentially consists of at     least one (preferably one) immunoglobulin single variable domain     (preferably Nanobody) directed against (human) CXCR7 and at least     one (preferably one) immunoglobulin single variable domain     (preferably Nanobody) directed against (human) CXCR4 (optionally     linked chemically or via one or more suitable linkers or spacers). -   Aspect K-10: Polypeptide that comprises or essentially consists of     at least one (preferably one) immunoglobulin single variable domain     (preferably Nanobody) directed against (human) CXCR7, at least one     (preferably one) immunoglobulin single variable domain (preferably     Nanobody) directed against (human) CXCR4, and a peptide or     immunoglobulin single variable domain (preferably Nanobody) directed     against (human) serum albumin (optionally linked chemically or via     one or more suitable linkers or spacers). -   Aspect K-11: Polypeptide that comprises or essentially consists of     two immunoglobulin single variable domains (preferably Nanobody)     directed against (human) CXCR7, which are the same (optionally     linked chemically or via one or more suitable linkers or spacers). -   Aspect K-12: Polypeptide that comprises or essentially consists of     two immunoglobulin single variable domains (preferably Nanobody)     directed against (human) CXCR7, which are different from each other     (optionally linked chemically or via one or more suitable linkers or     spacers). -   Aspect K-13: Polypeptide that comprises or essentially consists of     two immunoglobulin single variable domains (preferably Nanobody)     directed against (human) CXCR7, which are the same, and a peptide or     immunoglobulin single variable domain (preferably Nanobody) directed     against (human) serum albumin (optionally linked chemically or via     one or more suitable linkers or spacers). -   Aspect K-14: Polypeptide that comprises or essentially consists of     two immunoglobulin single variable domains (preferably Nanobody)     directed against (human) CXCR7, which are different from each other,     and a peptide or immunoglobulin single variable domain (preferably     Nanobody) directed against (human) serum albumin (optionally linked     chemically or via one or more suitable linkers or spacers).     Nucleic Acid -   Aspect M-1: Nucleic acid or nucleotide sequence, that encodes an     immunoglobulin single variable domain according to any of aspects     A-1 to A-22, B-1 to B-7, C-1 to C-4, D-1 to D-6, E-1 to E-13, a     polypeptide according to any of aspects K-1 to K-4. -   Aspect M-2: Nucleic acid or nucleotide sequence with SEQ ID NOs:     59-63 and 73-77 (Table B-6).     Host Cell -   Aspect N-1: Host or host cell that expresses, or that under suitable     circumstances is capable of expressing, an immunoglobulin single     variable domain according to any of aspects A-1 to A-22, B-1 to B-7,     C-1 to C-4, D-1 to D-6, E-1 to E-13, a polypeptide according to any     of aspects K-1 to K-4; and/or that comprises a nucleic acid or     nucleotide sequence according to aspect M-1 or M-2.     Compositions -   Aspect O-1: Composition comprising at least one immunoglobulin     single variable domain according to any of aspects A-1 to A-22, B-1     to B-7, C-1 to C-4, D-1 to D-6, E-1 to E-13, or at least one     polypeptide according to any of aspects K-1 to K-4, or nucleic acid     or nucleotide sequence according to aspects M-1 or M-2. -   Aspect O-2: Composition according to aspect O-1, which is a     pharmaceutical composition. -   Aspect O-3: Composition according to aspect O-2, which is a     pharmaceutical composition, that further comprises at least one     pharmaceutically acceptable carrier, diluent or excipient and/or     adjuvant, and that optionally comprises one or more further     pharmaceutically active polypeptides and/or compounds.     Making of Agent and Composition of the Invention -   Aspect P-1: Method for producing an immunoglobulin single variable     domain according to any of aspects A-1 to A-22, B-1 to B-7, C-1 to     C-4, D-1 to D-6, E-1 to E-13, a polypeptide according to any of     aspects K-1 to K-4, said method at least comprising the steps of:     -   a) expressing, in a suitable host cell or host organism or in         another suitable expression system, a nucleic acid or nucleotide         sequence according to aspect M-1, or aspect M-2;     -   optionally followed by:     -   b) isolating and/or purifying the immunoglobulin single variable         domain according to any of aspects A-1 to A-22, B-1 to B-7, C-1         to C-4, D-1 to D-6, E-1 to E-13, a polypeptide according to any         of aspects K-1 to K-4. -   Aspect P-2: Method for producing an immunoglobulin single variable     domain according to any of aspects A-1 to A-22, B-1 to B-7, C-1 to     C-4, D-1 to D-6, E-1 to E-13, a polypeptide according to any of     aspects K-1 to K-4, said method at least comprising the steps of:     -   a) cultivating and/or maintaining a host or host cell according         to aspect . . . under conditions that are such that said host or         host cell expresses and/or produces at least one immunoglobulin         single variable domain according to any of aspects A-1 to A-22,         B-1 to B-7, C-1 to C-4, D-1 to D-6, E-1 to E-13, a polypeptide         according to any of aspects K-1 to K-4;     -   optionally followed by:     -   b) isolating and/or purifying the immunoglobulin single variable         domain according to any of aspects A-1 to A-22, B-1 to B-7, C-1         to C-4, D-1 to D-6, E-1 to E-13, a polypeptide according to any         of aspects K-1 to K-4.         Method of Screening -   Aspect Q-1: Method for screening immunoglobulin single variable     domains directed against CXCR7 and in particular human CXCR7 (SEQ ID     NO: 1) that comprises at least the steps of:     -   a) providing a set, collection or library of nucleic acid         sequences encoding immunoglobulin single variable domains;     -   b) screening said set, collection or library of nucleic acid         sequences for nucleic acid sequences that encode an         immunoglobulin single variable domain that can bind to and/or         has affinity for CXCR7 and in particular human CXCR7 (SEQ ID         NO: 1) and that is cross-blocked or is cross blocking a Nanobody         of the invention, e.g. SEQ ID NO: 39 to 43 (Table-B-3), or a         polypeptide or construct of the invention, e.g. SEQ ID NO: 44 to         48 (see Table B-4); and     -   c) isolating said nucleic acid sequence, followed by expressing         said immunoglobulin single variable domain.         Use of Agents of the Invention -   Aspect R-1: Method for the prevention and/or treatment of cancer and     of inflammatory diseases (such as e.g. mentioned herein), said     method comprising administering, to a subject in need thereof, a     pharmaceutically active amount of at least one immunoglobulin single     variable domain according to any of aspects A-1 to A-22, B-1 to B-7,     C-1 to C-4, D-1 to D-6, E-1 to E-13, a polypeptide according to any     of aspects K-1 to K-4; or composition according to aspect O-2 or     O-3. -   Aspect R-2: Method for the prevention and/or treatment of at least     one disease or disorder that is associated with CXCR7 and in     particular human CXCR7 (SEQ ID NO: 1), with its biological or     pharmacological activity, and/or with the biological pathways or     signalling in which CXCR7 and in particular human CXCR7 (SEQ ID     NO: 1) is involved, said method comprising administering, to a     subject in need thereof, a pharmaceutically active amount of at     least one immunoglobulin single variable domain according to any of     aspects A-1 to A-22, B-1 to B-7, C-1 to C-4, D-1 to D-6, E-1 to     E-13, a polypeptide according to any of aspects K-1 to K-4; or     composition according to aspect O-2 or O-3. -   Aspect R-3: Method for the prevention and/or treatment of at least     one disease or disorder that can be prevented and/or treated by     administering, to a subject in need thereof, at least one     immunoglobulin single variable domain according to any of aspects     A-1 to A-22, B-1 to B-7, C-1 to C-4, D-1 to D-6, E-1 to E-13, a     polypeptide according to any of aspects K-1 to K-4; or composition     according to aspect O-2 or O-3, said method comprising     administering, to a subject in need thereof, a pharmaceutically     active amount of at least one at least one immunoglobulin single     variable domain according to any of aspects A-1 to A-22, B-1 to B-7,     C-1 to C-4, D-1 to D-6, E-1 to E-13, a polypeptide according to any     of aspects K-1 to K-4; or composition according to aspect O-2 or     O-3. -   Aspect R-4: Method for immunotherapy, said method comprising     administering, to a subject in need thereof, a pharmaceutically     active amount of at least one immunoglobulin single variable domain     according to any of aspects A-1 to A-22, B-1 to B-7, C-1 to C-4, D-1     to D-6, E-1 to E-13, a polypeptide according to any of aspects K-1     to K-4; or composition according to aspect O-2 or O-3. -   Aspect R-5: An immunoglobulin single variable domain according to     any of aspects A-1 to A-22, B-1 to B-7, C-1 to C-4, D-1 to D-6, E-1     to E-13, a polypeptide according to any of aspects K-1 to K-4, a     pharmaceutical composition according to aspect O-2 or O-3 for use in     one or more of the methods according to aspects R-1 to R-3. -   Aspect R-6: A polypeptide according to any of aspects K-1 to K-4,     for the diagnosis, prevention and/or treatment of cancer.     Further Aspects: -   1. An immunoglobulin single variable domain that can specifically     displace SDF-1 and/or I-TAC on human CXCR7 (SEQ ID NO: 1) with an     average Ki of less than 1000 nM, more preferably less than 500 nM,     more preferably less than 100 nM, even more preferably less than 50     nM, most preferably less than 10 nM and an average SDF-1 and/or     I-TAC displacement of 60% to 80% or more (in the radioligand assay     as e.g. outlined in example 9) or 80% to 100% (in the FACS     competition assay as e.g. outlined in example 10). -   2. The immunoglobulin single variable domain of aspect 1, wherein     the immunoglobulin single variable domain comprises an amino acid     sequence with the formula 1     FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4  (1);     -   wherein FR1 to FR4 refer to framework regions 1 to 4 and are         framework regions of an immunoglobulin single variable domain;     -   and wherein CDR1 is chosen from the group consisting of:         -   a) the immunoglobulin single variable domains of SEQ ID NO:             9,         -   b) immunoglobulin single variable domains that have at least             80% amino acid identity with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 9,         -   c) immunoglobulin single variable domains that have 3, 2, or             1 amino acid difference with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 9,     -   and wherein CDR2 is chosen from the group consisting of:         -   d) the immunoglobulin single variable domain of SEQ ID NO:             19;         -   e) immunoglobulin single variable domains that have at least             80% amino acid identity with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 19;         -   f) immunoglobulin single variable domains that have 3, 2, or             1 amino acid difference with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 19;     -   and wherein CDR3 is chosen from the group consisting of:         -   g) the immunoglobulin single variable domains of SEQ ID NO:             29;         -   h) immunoglobulin single variable domains that have at least             80% amino acid identity with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 29;         -   i) immunoglobulin single variable domains that have 3, 2, or             1 amino acid difference with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 29. -   3. The immunoglobulin single variable domain of aspect 1, wherein     the immunoglobulin single variable domain comprises an amino acid     sequence with the formula 1     FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4  (1);     -   wherein FR1 to FR4 refer to framework regions 1 to 4 and are         framework regions of an immunoglobulin single variable domain;     -   and wherein CDR1 is chosen from the group consisting of:         -   a) the immunoglobulin single variable domains of SEQ ID NO:             10,         -   b) immunoglobulin single variable domains that have at least             80% amino acid identity with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 10,         -   c) immunoglobulin single variable domains that have 3, 2, or             1 amino acid difference with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 10,     -   and wherein CDR2 is chosen from the group consisting of:         -   d) the immunoglobulin single variable domain of SEQ ID NO:             20;         -   e) immunoglobulin single variable domains that have at least             80% amino acid identity with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 20;         -   f) immunoglobulin single variable domains that have 3, 2, or             1 amino acid difference with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 20;     -   and wherein CDR3 is chosen from the group consisting of:         -   g) the immunoglobulin single variable domains of SEQ ID NO:             30;         -   h) immunoglobulin single variable domains that have at least             80% amino acid identity with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 30;         -   i) immunoglobulin single variable domains that have 3, 2, or             1 amino acid difference with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 30. -   4. The immunoglobulin single variable domain of aspect 1, wherein     the immunoglobulin single variable domain comprises an amino acid     sequence with the formula 1     FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4  (1);     -   wherein FR1 to FR4 refer to framework regions 1 to 4 and are         framework regions of an immunoglobulin single variable domain;     -   and wherein CDR1 is chosen from the group consisting of:         -   a) the immunoglobulin single variable domains of SEQ ID NO:             11,         -   b) immunoglobulin single variable domains that have at least             80% amino acid identity with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 11,         -   c) immunoglobulin single variable domains that have 3, 2, or             1 amino acid difference with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 11,     -   and wherein CDR2 is chosen from the group consisting of:         -   d) the immunoglobulin single variable domain of SEQ ID NO:             21;         -   e) immunoglobulin single variable domains that have at least             80% amino acid identity with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 21;         -   f) immunoglobulin single variable domains that have 3, 2, or             1 amino acid difference with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 21;     -   and wherein CDR3 is chosen from the group consisting of:         -   g) the immunoglobulin single variable domains of SEQ ID NO:             31;         -   h) immunoglobulin single variable domains that have at least             80% amino acid identity with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 31;         -   i) immunoglobulin single variable domains that have 3, 2, or             1 amino acid difference with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 31. -   5. The immunoglobulin single variable domain of aspect 1, wherein     the immunoglobulin single variable domain comprises an amino acid     sequence with the formula 1     FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4  (1);     -   wherein FR1 to FR4 refer to framework regions 1 to 4 and are         framework regions of an immunoglobulin single variable domain;     -   and wherein CDR1 is chosen from the group consisting of:         -   a) the immunoglobulin single variable domains of SEQ ID NO:             12,         -   b) immunoglobulin single variable domains that have at least             80% amino acid identity with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 12,         -   c) immunoglobulin single variable domains that have 3, 2, or             1 amino acid difference with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 12,     -   and wherein CDR2 is chosen from the group consisting of:         -   d) the immunoglobulin single variable domain of SEQ ID NO:             22;         -   e) immunoglobulin single variable domains that have at least             80% amino acid identity with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 22;         -   f) immunoglobulin single variable domains that have 3, 2, or             1 amino acid difference with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 22;     -   and wherein CDR3 is chosen from the group consisting of:         -   g) the immunoglobulin single variable domains of SEQ ID NO:             32;         -   h) immunoglobulin single variable domains that have at least             80% amino acid identity with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 32;         -   i) immunoglobulin single variable domains that have 3, 2, or             1 amino acid difference with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 32. -   6. The immunoglobulin single variable domain of aspect 1, wherein     the immunoglobulin single variable domain comprises an amino acid     sequence with the formula 1     FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4  (1);     -   wherein FR1 to FR4 refer to framework regions 1 to 4 and are         framework regions of an immunoglobulin single variable domain;     -   and wherein CDR1 is chosen from the group consisting of:         -   a) the immunoglobulin single variable domains of SEQ ID NO:             13,         -   b) immunoglobulin single variable domains that have at least             80% amino acid identity with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 13,         -   c) immunoglobulin single variable domains that have 3, 2, or             1 amino acid difference with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 13,     -   and wherein CDR2 is chosen from the group consisting of:         -   d) the immunoglobulin single variable domain of SEQ ID NO:             23;         -   e) immunoglobulin single variable domains that have at least             80% amino acid identity with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 23;         -   f) immunoglobulin single variable domains that have 3, 2, or             1 amino acid difference with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 23;     -   and wherein CDR3 is chosen from the group consisting of:         -   g) the immunoglobulin single variable domains of SEQ ID NO:             33;         -   h) immunoglobulin single variable domains that have at least             80% amino acid identity with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 33;         -   i) immunoglobulin single variable domains that have 3, 2, or             1 amino acid difference with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 33. -   7. The immunoglobulin single variable domain of aspect 1, wherein     the immunoglobulin single variable domain comprises an amino acid     sequence with the formula 1     FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4  (1);     -   wherein FR1 to FR4 refer to framework regions 1 to 4 and are         framework regions of an immunoglobulin single variable domain;     -   and wherein CDR1 is chosen from the group consisting of:         -   a) the immunoglobulin single variable domains of SEQ ID NO:             14,         -   b) immunoglobulin single variable domains that have at least             80% amino acid identity with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 14,         -   c) immunoglobulin single variable domains that have 3, 2, or             1 amino acid difference with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 14,     -   and wherein CDR2 is chosen from the group consisting of:         -   d) the immunoglobulin single variable domain of SEQ ID NO:             24;         -   e) immunoglobulin single variable domains that have at least             80% amino acid identity with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 24;         -   f) immunoglobulin single variable domains that have 3, 2, or             1 amino acid difference with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 24;     -   and wherein CDR3 is chosen from the group consisting of:         -   g) the immunoglobulin single variable domains of SEQ ID NO:             34;         -   h) immunoglobulin single variable domains that have at least             80% amino acid identity with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 34;         -   i) immunoglobulin single variable domains that have 3, 2, or             1 amino acid difference with at least one of the             immunoglobulin single variable domains of SEQ ID NO: 34. -   8. The immunoglobulin single variable domain according to any of     aspects 2 to 7, wherein the framework regions (FRs) have a sequence     identity of more than 80% (more preferably 85%, even more preferably     90%, most preferred 95%) with the FRs of SEQ ID NOs: 4 to 8 (FR1),     14 to 18 (FR2), 24 to 28 (FR3), 34 to 38 (FR4). -   9. A polypeptide comprising an immunoglobulin single variable domain     of any of aspects 1 to 8. -   10. The polypeptide according to aspect 9, wherein the polypeptide     is selected from the group consisting of polypeptides that have an     amino acid sequence with a sequence identity of more than 80% (more     preferably 85%, even more preferably 90%, most preferred 95%) with     the of SEQ ID NOs: 39 to 43. -   11. The polypeptide according to any of aspects 9 to 10 and     additionally comprising an immunoglobulin single variable domain     that binds human serum albumin such as e.g. Alb8 (SEQ ID NO: 2). -   12. The polypeptides according to any of aspects 9 to 11, wherein     the polypeptide is selected from the group consisting of     polypeptides that have an amino acid sequence with a sequence     identity of more than 80% (more preferably 85%, even more preferably     90%, most preferred 95%) with the of SEQ ID NOs: 44 to 48. -   13. A nucleic acid sequence encoding i) for an immunoglobulin single     variable domain according to any of aspects 1 to 8; or ii) for a     polypeptide according to any of aspects 9 to 12. -   14. A pharmaceutical composition comprising i) an immunoglobulin     single variable domain according to any of aspects 1 to 8; or ii) a     polypeptide according to any of aspects 9 to 12; and optionally a     pharmaceutically acceptable excipient. -   15. An immunoglobulin single variable domain according to any of     aspects 1 to 8 or a polypeptide according to any of aspects 9 to 12     for use in cancer. -   16. Method for producing an immunoglobulin single variable domain     according to any of aspects 1 to 9 or a polypeptide according to any     of aspects 9 to 12, said method at least comprising the steps of:     -   a) expressing, in a suitable host cell or host organism or in         another suitable expression system, a nucleic acid or nucleotide         sequence according to aspect 13; optionally followed by:     -   b) isolating and/or purifying the immunoglobulin single variable         domain according to any of aspects 1 to 9 or a polypeptide         according to any of aspects 9 to 12. -   17. The immunoglobulin single variable domain of aspect 1, wherein     the immunoglobulin single variable domain comprises an amino acid     sequence with the formula 1     FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4  (1);     -   wherein FR1 to FR4 refer to framework regions 1 to 4 and are         framework regions of an immunoglobulin single variable domain;     -   and wherein CDR1 is the immunoglobulin single variable domains         of SEQ ID NO: 9,     -   and wherein CDR2 is the immunoglobulin single variable domain of         SEQ ID NO: 19;     -   and wherein CDR3 is the immunoglobulin single variable domains         of SEQ ID NO: 29. -   18. The immunoglobulin single variable domain of aspect 1, wherein     the immunoglobulin single variable domain comprises an amino acid     sequence with the formula 1     FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4  (1);     -   wherein FR1 to FR4 refer to framework regions 1 to 4 and are         framework regions of an immunoglobulin single variable domain;     -   and wherein CDR1 is the immunoglobulin single variable domains         of SEQ ID NO: 10,     -   and wherein CDR2 is the immunoglobulin single variable domain of         SEQ ID NO: 20;     -   and wherein CDR3 is the immunoglobulin single variable domains         of SEQ ID NO: 30. -   19. The immunoglobulin single variable domain of aspect 1, wherein     the immunoglobulin single variable domain comprises an amino acid     sequence with the formula 1     FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4  (1);     -   wherein FR1 to FR4 refer to framework regions 1 to 4 and are         framework regions of an immunoglobulin single variable domain;     -   and wherein CDR1 is the immunoglobulin single variable domains         of SEQ ID NO: 11,     -   and wherein CDR2 is the immunoglobulin single variable domain of         SEQ ID NO: 21;     -   and wherein CDR3 is the immunoglobulin single variable domains         of SEQ ID NO: 31. -   20. The immunoglobulin single variable domain of aspect 1, wherein     the immunoglobulin single variable domain comprises an amino acid     sequence with the formula 1     FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4  (1);     -   wherein FR1 to FR4 refer to framework regions 1 to 4 and are         framework regions of an immunoglobulin single variable domain;     -   and wherein CDR1 is the immunoglobulin single variable domains         of SEQ ID NO: 12,     -   and wherein CDR2 is the immunoglobulin single variable domain of         SEQ ID NO: 22;     -   and wherein CDR3 is the immunoglobulin single variable domains         of SEQ ID NO: 32. -   21. The immunoglobulin single variable domain of aspect 1, wherein     the immunoglobulin single variable domain comprises an amino acid     sequence with the formula 1     FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4  (1);     -   wherein FR1 to FR4 refer to framework regions 1 to 4 and are         framework regions of an immunoglobulin single variable domain;     -   and wherein CDR1 is the immunoglobulin single variable domains         of SEQ ID NO: 13,     -   and wherein CDR2 is the immunoglobulin single variable domain of         SEQ ID NO: 23;     -   and wherein CDR3 is the immunoglobulin single variable domains         of SEQ ID NO: 33. -   22. The immunoglobulin single variable domain of aspect 1, wherein     the immunoglobulin single variable domain comprises an amino acid     sequence with the formula 1     FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4  (1);     -   wherein FR1 to FR4 refer to framework regions 1 to 4 and are         framework regions of an immunoglobulin single variable domain;     -   and wherein CDR1 is the immunoglobulin single variable domains         of SEQ ID NO: 14,     -   and wherein CDR2 is the immunoglobulin single variable domain of         SEQ ID NO: 24;     -   and wherein CDR3 is the immunoglobulin single variable domains         of SEQ ID NO: 34.

EXPERIMENTAL PART

Sequences

TABLE B-1 Prior art sequences SEQ ID Name NO: Amino acid sequences Human 1 MDLHLFDYSEPGNFSDISWPCNSSDCIVVDTV CXCR7 MCPNMPNKSVLLYTLSFIYIFIFVIGMIANSVVV or WVNIQAKTTGYDTHCYILNLAIADLWVVLTIP hCXCR7 VWVVSLVQHNQWPMGELTCKVTHLIFSINLFG SIFFLTCMSVDRYLSITYFTNTPSSRKKMVRRV VCILVWLLAFCVSLPDTYYLKTVTSASNNETY CRSFYPEHSIKEWLIGMELVSVVLGFAVPFSIIA VFYFLLARAISASSDQEKHSSRKIIFSYVVVFLV CWLPYHVAVLLDIFSILHYIPFTCRLEHALFTAL HVTQCLSLVHCCVNPVLYSFINRNYRYELMKA FIFKYSAKTGLTKLIDASRVSETEYSALEQSTK Alb8 2 EVQLVESGGGLVQPGNSLRLSCAASGFTFSSFG MSWVRQAPGKGLEWVSSISGSGSDTLYADSVK GRFTISRDNAKTTLYLQMNSLRPEDTAVYYCTI GGSLSRSSQGTLVTVSS Mouse 3 MDVHLFDYAEPGNYSDINWPCNSSDCIVVDTV CXCR7 QCPTMPNKNVLLYTLSFIYIFIFVIGMIANSVVV or WVNIQAKTTGYDTHCYILNLAIADLWVVITIPV mCXCR7 WVVSLVQHNQWPMGELTCKITHLIFSINLFGSI FFLACMSVDRYLSITYFTGTSSYKKKMVRRVV CILVWLLAFFVSLPDTYYLKTVTSASNNETYCR SFYPEHSIKEWLIGMELVSVILGFAVPFTIIAIFY FLLARAMSASGDQEKHSSRKIIFSYVVVFLVCW LPYHFVVLLDIFSILHYIPFTCQLENVLFTALHV TQCLSLVHCCVNPVLYSFINRNYRYELMKAFIF KYSAKTGLTKLIDASRVSETEYSALEQNTK Tag-1 71 AAAHHHHHHGAAEQKLISEEDLNGAA Tag-2 72 AAAEQKLISEEDLNGAAHHHHHH Cyno- 90 MDLHVFDYSEPGNFSDISWPCNSSDCIVVDTV moglous MCPNMPNKSVLLYTLAFIYIFIFVIGMIANSVVV CXCR7 or WVNIQAKTTGYDTHCYILNLAIADLWVVLTIP cCXCR7 VWVVSLVQHNQWPMGELTCKVTHLIFSINLFG SIFFLTCMSVDRYLSITYFTNTSSSRKKMVRRV VCVLVWLLAFCVSLPDTYYLKTVTSASNNETY CRSFYPEHSIKEWLIGMELVSVVLGFAVPFSVIA VFYFLLARAISASGDQEKHSSRKIIFSYVVVFLV CWLPYHVAVLLDIFSILHYIPFTCRLEHALFTAL HVTQCLSLVHCCVNPVLYSFINRNYRYELMKA FIFKYSAKTGLTKLIDASRVSETEYSALEQSTK

TABLE B-2 Sequences for CDRs and frameworks, plus preferred combinations as provided in for formula I, namely FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4 Clone ID FR1 ID CDR1 ID FR2 07B11 4 EVQLVESGGNLVQAGGSLGL 9 IHIMG 14 WYRQAPGKQRDL SCAASVSISS VA 07C3 5 EVQLVESGGGLVQAGESLTLS 10 AYIMG 15 WFRQAPGKEREF CAASGRTLS VA 08A5 6 EVQLVESGGGLVQAGDSLRL 11 NYDMG 16 WFRQAPGKEREF SCAASGLTFS VG 08A10 7 EVQLVESGGGLVQAGGSLRL 12 IAAMG 17 WYRQATGKQREL SCAASGSIFS VA 14G3 8 EVQLVESGGGLVQPGGSLRIS 13 INYMG 18 WYRQAPGKQREL CAASGSIYL VA Alb8 64 EVQLVESGGGLVQPGNSLRLS 65 SFGMS 66 WVRQAPGKGLEW CAASGFTFS VS Clone ID CDR2 ID FR3 07B11 19 TITSGGSTAYADSVKG 24 RFTVSKDNAKNTVYLQMDSLKPEDTS VYYCAA 07C3 20 GIWSGGYTHLADSAK 25 RFSISRDNAKNTVYLQMNGLKPEDTA G VYYCAA 08A5 21 ASWWSGGAPYYSDSV 26 RFTISRDNAKNTVYLQANSLRPEDTAV KG YYCAA 08A10 22 TITDGGTTTYADSVKG 27 RVTISRDRSANTVYLAMNNLKPDDTA VYYCYA 14G3 23 TLTSGGSTNYAGSVKG 28 RFAISRDNAKNTVYLQMNSLKPEDTA VYYCNI Alb8 67 SISGSGSDTLYADSVK 68 RFTISRDNAKTTLYLQMNSLRPEDTAV G YYCTI Clone ID CDR3 ID FR4 07B11 29 EVRNGVFGKWNHY 34 WGQGTQVTVSS 07C3 30 GLRGRQYSN 35 WGQGTQVTVSS 08A5 31 KRLRSFASGGSYDY 36 WGQGTQVTVSS 08A10 32 YLRYTSRVPGDNY  37 WGQGTQVTVSS 14G3 33 GGTLYDRRRFES 38 WGQGTQVTVSS Alb8 69 GGSLSR 70 SSQGTLVTVSS (the following terms: “ID” refers to the given SEQ ID NO. Preferred combination of FR and CDR sequences for each NB construct are used interchangeably through-out the application)

TABLE B-3 Amino acid sequences of immunoglobulin single variable sequences of the invention SEQ Name of ID clone NO: Amino acid sequences 07B11 39 EVQLVESGGNLVQAGGSLGLSCAASVSISSIHI MGWYRQAPGKQRDLVATITSGGSTAYADSVK GRFTVSKDNAKNTVYLQMDSLKPEDTSVYYC AAEVRNGVFGKWNHYWGQGTQVTVSS 07C3 40 EVQLVESGGGLVQAGESLTLSCAASGRTLSAYI MGWFRQAPGKEREFVAGIWSGGYTHLADSAK GRFSISRDNAKNTVYLQMNGLKPEDTAVYYCA AGLRGRQYSNWGQGTQVTVSS 08A5 41 EVQLVESGGGLVQAGDSLRLSCAASGLTFSNY DMGWFRQAPGKEREFVGASWWSGGAPYYSD SVKGRFTISRDNAKNTVYLQANSLRPEDTAVY YCAAKRLRSFASGGSYDYWGQGTQVTVSS 08A10 42 EVQLVESGGGLVQAGGSLRLSCAASGSIFSIAA MGWYRQATGKQRELVATITDGGTTTYADSVK GRVTISRDRSANTVYLAMNNLKPDDTAVYYC YAYLRYTSRVPGDNYWGQGTQVTVSS 14G3 43 EVQLVESGGGLVQPGGSLRISCAASGSIYLINY MGWYRQAPGKQRELVATLTSGGSTNYAGSVK GRFAISRDNAKNTVYLQMNSLKPEDTAVYYCN IGGTLYDRRRFESWGQGTQVTVSS

TABLE B-4 Polypeptide sequences of the invention SEQ Name of ID clone NO: Amino acid sequences 07B11-9GS- 44 EVQLVESGGNLVQAGGSLGLSCAASVSISSIHI Alb8 MGWYRQAPGKQRDLVATITSGGSTAYADSVK GRFTVSKDNAKNTVYLQMDSLKPEDTSVYYC AAEVRNGVFGKWNHYWGQGTQVTVSSGGGG SGGGSEVQLVESGGGLVQPGNSLRLSCAASGF TFSSFGMSWVRQAPGKGLEWVSSISGSGSDTL YADSVKGRFTISRDNAKTTLYLQMNSLRPEDT AVYYCTIGGSLSRSSQGTLVTVSS 07C3-9GS- 45 EVQLVESGGGLVQAGESLTLSCAASGRTLSAYI Alb8 MGWFRQAPGKEREFVAGIWSGGYTHLADSAK GRFSISRDNAKNTVYLQMNGLKPEDTAVYYCA AGLRGRQYSNWGQGTQVTVSSGGGGSGGGSE VQLVESGGGLVQPGNSLRLSCAASGFTFSSFG MSWVRQAPGKGLEWVSSISGSGSDTLYADSVK GRFTISRDNAKTTLYLQMNSLRPEDTAVYYCTI GGSLSRSSQGTLVTVSS 08A5-9GS- 46 EVQLVESGGGLVQAGDSLRLSCAASGLTFSNY Alb8 DMGWFRQAPGKEREFVGASWWSGGAPYYSD SVKGRFTISRDNAKNTVYLQANSLRPEDTAVY YCAAKRLRSFASGGSYDYWGQGTQVTVSSGG GGSGGGSEVQLVESGGGLVQPGNSLRLSCAAS GFTFSSFGMSWVRQAPGKGLEWVSSISGSGSD TLYADSVKGRFTISRDNAKTTLYLQMNSLRPE DTAVYYCTIGGSLSRSSQGTLVTVSS 08A10-9GS- 47 EVQLVESGGGLVQAGGSLRLSCAASGSIFSIAA Alb8 MGWYRQATGKQRELVATITDGGTTTYADSVK GRVTISRDRSANTVYLAMNNLKPDDTAVYYC YAYLRYTSRVPGDNYWGQGTQVTVSSGGGGS GGGSEVQLVESGGGLVQPGNSLRLSCAASGFT FSSFGMSWVRQAPGKGLEWVSSISGSGSDTLY ADSVKGRFTISRDNAKTTLYLQMNSLRPEDTA VYYCTIGGSLSRSSQGTLVTVSS 14G3-9GS- 48 EVQLVESGGGLVQPGGSLRISCAASGSIYLINY Alb8 MGWYRQAPGKQRELVATLTSGGSTNYAGSVK GRFAISRDNAKNTVYLQMNSLKPEDTAVYYCN IGGTLYDRRRFESWGQGTQVTVSSGGGGSGGG SEVQLVESGGGLVQPGNSLRLSCAASGFTFSSF GMSWVRQAPGKGLEWVSSISGSGSDTLYADSV KGRFTISRDNAKTTLYLQMNSLRPEDTAVYYC TIGGSLSRSSQGTLVTVSS 07B11-9GS- 78 EVQLVESGGNLVQAGGSLGLSCAASVSISSIHI 07C3 MGWYRQAPGKQRDLVATITSGGSTAYADSVK GRFTVSKDNAKNTVYLQMDSLKPEDTSVYYC AAEVRNGVFGKWNHYWGQGTQVTVSSGGGG SGGGSEVQLVESGGGLVQAGESLTLSCAASGR TLSAYIMGWFRQAPGKEREFVAGIWSGGYTHL ADSAKGRFSISRDNAKNTVYLQMNGLKPEDTA VYYCAAGLRGRQYSNWGQGTQVTVSS 07C3-9GS- 79 EVQLVESGGGLVQAGESLTLSCAASGRTLSAYI 01311 MGWFRQAPGKEREFVAGIWSGGYTHLADSAK GRFSISRDNAKNTVYLQMNGLKPEDTAVYYCA AGLRGRQYSNWGQGTQVTVSSGGGGSGGGSE VQLVESGGNLVQAGGSLGLSCAASVSISSIHIM GWYRQAPGKQRDLVATITSGGSTAYADSVKG RFTVSKDNAKNTVYLQMDSLKPEDTSVYYCA AEVRNGVFGKWNHYWGQGTQVTVSS 07B11-9GS- 80 EVQLVESGGNLVQAGGSLGLSCAASVSISSIHI Alb8-9GS- MGWYRQAPGKQRDLVATITSGGSTAYADSVK 07C3 GRFTVSKDNAKNTVYLQMDSLKPEDTSVYYC AAEVRNGVFGKWNHYWGQGTQVTVSSGGGG SGGGSEVQLVESGGGLVQPGNSLRLSCAASGF TFSSFGMSWVRQAPGKGLEWVSSISGSGSDTL YADSVKGRFTISRDNAKTTLYLQMNSLRPEDT AVYYCTIGGSLSRSSQGTLVTVSSGGGGSGGGS EVQLVESGGGLVQAGESLTLSCAASGRTLSAYI MGWFRQAPGKEREFVAGIWSGGYTHLADSAK GRFSISRDNAKNTVYLQMNGLKPEDTAVYYCA AGLRGRQYSNWGQGTQVTVSS 07B11-9GS- 81 EVQLVESGGNLVQAGGSLGLSCAASVSISSIHI 07C3-9GS- MGWYRQAPGKQRDLVATITSGGSTAYADSVK Alb8 GRFTVSKDNAKNTVYLQMDSLKPEDTSVYYC AAEVRNGVFGKWNHYWGQGTQVTVSSGGGG SGGGSEVQLVESGGGLVQAGESLTLSCAASGR TLSAYIMGWFRQAPGKEREFVAGIWSGGYTHL ADSAKGRFSISRDNAKNTVYLQMNGLKPEDTA VYYCAAGLRGRQYSNWGQGTQVTVSSGGGGS GGGSEVQLVESGGGLVQPGNSLRLSCAASGFT FSSFGMSWVRQAPGKGLEWVSSISGSGSDTLY ADSVKGRFTISRDNAKTTLYLQMNSLRPEDTA VYYCTIGGSLSRSSQGTLVTVSS 08A5-9GS- 82 EVQLVESGGGLVQAGDSLRLSCAASGLTFSNY 08A10 DMGWFRQAPGKEREFVGASWWSGGAPYYSD SVKGRFTISRDNAKNTVYLQANSLRPEDTAVY YCAAKRLRSFASGGSYDYWGQGTQVTVSSGG GGSGGGSEVQLVESGGGLVQAGGSLRLSCAAS GSIFSIAAMGWYRQATGKQRELVATITDGGTT TYADSVKGRVTISRDRSANTVYLAMNNLKPDD TAVYYCYAYLRYTSRVPGDNYWGQGTQVTVS S 08A10-9GS- 83 EVQLVESGGGLVQAGGSLRLSCAASGSIFSIAA Alb8-9GS- MGWYRQATGKQRELVATITDGGTTTYADSVK 08A10 GRVTISRDRSANTVYLAMNNLKPDDTAVYYC YAYLRYTSRVPGDNYWGQGTQVTVSSGGGGS GGGSEVQLVESGGGLVQPGNSLRLSCAASGFT FSSFGMSWVRQAPGKGLEWVSSISGSGSDTLY ADSVKGRFTISRDNAKTTLYLQMNSLRPEDTA VYYCTIGGSLSRSSQGTLVTVSSGGGGSGGGSE VQLVESGGGLVQAGGSLRLSCAASGSIFSIAAM GWYRQATGKQRELVATITDGGTTTYADSVKG RVTISRDRSANTVYLAMNNLKPDDTAVYYCY AYLRYTSRVPGDNYWGQGTQVTVSS 08A10-9GS- 84 EVQLVESGGGLVQAGGSLRLSCAASGSIFSIAA 08A10-9GS- MGWYRQATGKQRELVATITDGGTTTYADSVK Alb8 GRVTISRDRSANTVYLAMNNLKPDDTAVYYC YAYLRYTSRVPGDNYWGQGTQVTVSSGGGGS GGGSEVQLVESGGGLVQAGGSLRLSCAASGSIF SIAAMGWYRQATGKQRELVATITDGGTTTYA DSVKGRVTISRDRSANTVYLAMNNLKPDDTAV YYCYAYLRYTSRVPGDNYWGQGTQVTVSSGG GGSGGGSEVQLVESGGGLVQPGNSLRLSCAAS GFTFSSFGMSWVRQAPGKGLEWVSSISGSGSD TLYADSVKGRFTISRDNAKTTLYLQMNSLRPE DTAVYYCTIGGSLSRSSQGTLVTVSS 08A5-9GS- 85 EVQLVESGGGLVQAGDSLRLSCAASGLTFSNY 08A10-9GS- DMGWFRQAPGKEREFVGASWWSGGAPYYSD Alb8 SVKGRFTISRDNAKNTVYLQANSLRPEDTAVY YCAAKRLRSFASGGSYDYWGQGTQVTVSSW GGSGGGSEVQLVESGGGLVQAGGSLRLSCAAS GSIFSIAAMGWYRQATGKQRELVATITDGGTT TYADSVKGRVTISRDRSANTVYLAMNNLKPDD TAVYYCYAYLRYTSRVPGDNYWGQGTQVTVS SGGGGSGGGSEVQLVESGGGLVQPGNSLRLSC AASGFTFSSFGMSWVRQAPGKGLEWVSSISGS GSDTLYADSVKGRFTISRDNAKTTLYLQMNSL RPEDTAVYYCTIGGSLSRSSQGTLVTVSS 07B11-9GS- 86 EVQLVESGGNLVQAGGSLGLSCAASVSISSIHI 238D2 (238D2 MGWYRQAPGKQRDLVATITSGGSTAYADSVK is directed GRFTVSKDNAKNTVYLQMDSLKPEDTSVYYC against AAEVRNGVFGKWNHYWGQGTQVTVSSGGGG CXCR4) SGGGSEVQLVESGGGLVQTGGSLRLSCAASGF TFSSYAMSWVRQAPGKGLEWVSGIKSSGDSTR YAGSVKGRFTISRDNAKNMLYLQMYSLKPEDT AVYYCAKSRVSRTGLYTYDNRGQGTQVTVSS 07C3-9GS- 87 EVQLVESGGGLVQAGESLTLSCAASGRTLSAYI 238D4 MGWFRQAPGKEREFVAGIWSGGYTHLADSAK (238D4 is GRFSISRDNAKNTVYLQMNGLKPEDTAVYYCA directed AGLRGRQYSNWGQGTQVTVSSGGGGSGGGSE against VQLMESGGGLVQAGGSLRLSCAASGRTFNNY CXCR4) AMGWERRAPGKEREFVAAITRSGVRSGVSAIY GDSVKDRFTISRDNAKNTLYLQMNSLKPEDTA VYTCAASAIGSGALRRFEYDYSGQGTQVTVSS 08A10-9GS- EVQLVESGGGLVQAGGSLRLSCAASGSIFSIAA Alb8-889GS- MGWYRQATGKQRELVATITDGGTTTYADSVK 238D2 GRVTISRDRSANTVYLAMNNLKPDDTAVYYC (238D2 is YAYLRYTSRVPGDNYWGQGTQVTVSSGGGGS directed GGGSEVQLVESGGGLVQPGNSLRLSCAASGFT against FSSFGMSWVRQAPGKGLEWVSSISGSGSDTLY CXCR4) ADSVKGRFTISRDNAKTTLYLQMNSLRPEDTA VYYCTIGGSLSRSSQGTLVTVSSGGGGSGGGSE VQLVESGGGLVQTGGSLRLSCAASGFTFSSYA MSWVRQAPGKGLEWVSGIKSSGDSTRYAGSV KGRFTISRDNAKNMLYLQMYSLKPEDTAVYY CAKSRVSRTGLYTYDNRGQGTQVTVSS 08A5-9GS- 89 EVQLVESGGGLVQAGDSLRLSCAASGLTFSNY 238D4-9GS- DMGWFRQAPGKEREFVGASWWSGGAPYYSD Alb8 SVKGRFTISRDNAKNTVYLQANSLRPEDTAVY (238D4 is YCAAKRLRSFASGGSYDYWGQGTQVTVSSGG directed GGSGGGSEVQLMESGGGLVQAGGSLRLSCAAS against GRTFNNYAMGWFRRAPGKEREFVAAITRSGVR CXCR4) SGVSAIYGDSVKDRFTISRDNAKNTLYLQMNS LKPEDTAVYTCAASAIGSGALRRFEYDYSGQG TQVTVSSGGGGSGGGSEVQLVESGGGLVQPGN SLRLSCAASGFTFSSFGMSWVRQAPGKGLEWV SSISGSGSDTLYADSVKGRFTISRDNAKTTLYL QMNSLRPEDTAVYYCTIGGSLSRSSQGTLVTVS S

TABLE B-5 Linker sequences of the invention Name of SEQ ID linker NO: Amino acid sequences  5GS 49 GGGGS  6GS 50 SGGSGGS  9GS 51 GGGGSGGGS 10GS 52 GGGGSGGGGS 15GS 53 GGGGSGGGGSGGGGS 18GS 54 GGGGSGGGGSGGGGGGGS 20GS 55 GGGGSGGGGSGGGGSGGGGS 25GS 56 GGGGSGGGGSGGGGSGGGGSGGGGS 30GS 57 GGGGSGGGGSGGGGSGGGGSGGGGSGGGGS 35GS 58 GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSG GGGS

TABLE B-6 Nucleic acid sequences of the invention SEQ Name of ID clone NO: Nucleic acid sequences 07B11 59 GAGGTGCAATTGGTGGAGTCTGGGGGAAACT TGGTGCAGGCTGGGGGGTCTCTGGGACTCTC CTGTGCAGCCTCTGTAAGCATCTCCAGTATCC ATATCATGGGCTGGTACCGGCAGGCTCCAGG CAAACAGCGCGACTTGGTCGCTACTATTACT AGTGGTGGTAGCACAGCATATGCAGACTCCG TGAAGGGACGATTCACCGTCTCCAAAGACAA CGCCAAGAACACGGTGTATCTGCAAATGGAC AGCCTGAAACCTGAGGACACATCCGTCTATT ACTGTGCAGCCGAGGTCAGAAATGGGGTGTT TGGAAAATGGAATCACTACTGGGGCCAGGG GACCCAGGTCACCGTCTCCTCA 07C3 60 GAGGTGCAATTGGTGGAGTCTGGGGGAGGAT TGGTGCAGGCTGGGGAGTCTCTGACTCTCTC CTGTGCAGCCTCTGGACGCACCTTAAGTGCC TATATCATGGGCTGGTTCCGCCAGGCTCCAG GGAAGGAGCGGGAGTTTGTAGCCGGTATCTG GAGTGGTGGTTACACACACCTTGCAGACTCC GCGAAGGGCCGATTCAGCATCTCTAGAGACA ACGCCAAGAACACTGTATATCTGCAAATGAA CGGCCTGAAACCTGAGGACACGGCCGTCTAT TACTGTGCAGCAGGTCTGAGAGGCCGCCAGT ATAGTAACTGGGGCCAGGGGACCCAGGTCAC CGTCTCCTCA 08A5 61 GAGGTGCAATTGGTGGAGTCTGGGGGAGGAT TGGTGCAGGCTGGGGACTCTCTGAGACTCTC CTGTGCAGCCTCTGGACTCACTTTCAGTAACT ATGACATGGGCTGGTTCCGCCAGGCTCCAGG GAAGGAGCGTGAATTTGTAGGGGCTAGTTGG TGGAGTGGTGGTGCCCCATACTATTCAGACT CCGTGAAGGGCCGATTCACCATCTCCAGAGA CAACGCCAAGAACACGGTGTATCTGCAAGCG AACAGCCTGAGACCTGAGGACACGGCCGTTT ATTACTGTGCAGCCAAAAGGCTGCGTAGTTT CGCCTCCGGTGGGTCGTATGATTACTGGGGT CAGGGGACCCAGGTCACCGTCTCCTCA 08A10 62 GAGTCTGGGGGAGGCTTGGTGCAGGCTGGAG GGTCTCTGAGACTCTCCTGTGCAGCTTCTGGA AGCATCTTCAGTATCGCTGCCATGGGCTGGT ACCGCCAGGCTACAGGGAAGCAGCGCGAGT TGGTCGCAACTATCACTGATGGCGGTACGAC AACCTATGCAGACTCCGTGAAGGGCCGAGTC ACCATCTCCAGGGACAGGTCTGCGAACACGG TGTATCTGGCAATGAACAATTTGAAACCTGA TGACACAGCCGTCTATTATTGTTATGCGTATC TGCGCTATACAAGCAGAGTACCTGGCGATAA CTACTGGGGCCAGGGGACCCAGGTCACCGTC TCCTCA 14G3 63 GAGGTGCAATTGGTGGAGTCTGGGGGAGGCT TGGTGCAGCCTGGGGGGTCTCTGAGAATTTC CTGTGCAGCCTCTGGAAGCATCTACCTTATC AATTACATGGGCTGGTACCGCCAGGCTCCAG GGAAGCAGCGCGAGTTGGTCGCAACGCTTAC TAGTGGTGGTAGTACCAACTATGCAGGCTCC GTGAAGGGCCGATTCGCCATCTCCAGAGACA ACGCCAAGAACACGGTTTATCTGCAAATGAA CAGCCTGAAACCTGAGGACACGGCCGTCTAT TACTGTAATATAGGAGGAACGCTATACGACA GAAGGCGGTTTGAATCCTGGGGCCAGGGGAC CCAGGTCACCGTCTCCTCAG 07B11-9GS-Alb8 73 GAGGTGCAATTGGTGGAGTCTGGGGGAAACT TGGTGCAGGCTGGGGGGTCTCTGGGACTCTC CTGTGCAGCCTCTGTAAGCATCTCCAGTATCC ATATCATGGGCTGGTACCGGCAGGCTCCAGG CAAACAGCGCGACTTGGTCGCTACTATTACT AGTGGTGGTAGCACAGCATATGCAGACTCCG TGAAGGGACGATTCACCGTCTCCAAAGACAA CGCCAAGAACACGGTGTATCTGCAAATGGAC AGCCTGAAACCTGAGGACACATCCGTCTATT ACTGTGCAGCCGAGGTCAGAAATGGGGTGTT TGGAAAATGGAATCACTACTGGGGCCAGGG GACCCAGGTCACGGTCTCCTCAGGAGGTGGC GGGTCCGGAGGCGGATCCGAGGTACAGCTG GTGGAGTCTGGGGGTGGCTTGGTGCAACCGG GTAACAGTCTGCGCCTTAGCTGCGCAGCGTC TGGCTTTACCTTCAGCTCCTTTGGCATGAGCT GGGTTCGCCAGGCTCCGGGAAAAGGACTGG AATGGGTTTCGTCTATTAGCGGCAGTGGTAG CGATACGCTCTACGCGGACTCCGTGAAGGGC CGTTTCACCATCTCCCGCGATAACGCCAAAA CTACACTGTATCTGCAAATGAATAGCCTGCG TCCTGAAGACACGGCCGTTTATTACTGTACT ATTGGTGGCTCGTTAAGCCGTTCTTCACAGG GTACCCTGGTCACCGTCTCCTCA 07C3-9GS-Alb8 74 GAGGTGCAATTGGTGGAGTCTGGGGGAGGAT TGGTGCAGGCTGGGGAGTCTCTGACTCTCTC CTGTGCAGCCTCTGGACGCACCTTAAGTGCC TATATCATGGGCTGGTTCCGCCAGGCTCCAG GGAAGGAGCGGGAGTTTGTAGCCGGTATCTG GAGTGGTGGTTACACACACCTTGCAGACTCC GCGAAGGGCCGATTCAGCATCTCTAGAGACA ACGCCAAGAACACTGTATATCTGCAAATGAA CGGCCTGAAACCTGAGGACACGGCCGTCTAT TACTGTGCAGCAGGTCTGAGAGGCCGCCAGT ATAGTAACTGGGGCCAGGGGACCCAGGTCAC GGTCTCCTCAGGAGGTGGCGGGTCCGGAGGC GGATCCGAGGTACAGCTGGTGGAGTCTGGGG GTGGCTTGGTGCAACCGGGTAACAGTCTGCG CCTTAGCTGCGCAGCGTCTGGCTTTACCTTCA GCTCCTTTGGCATGAGCTGGGTTCGCCAGGC TCCGGGAAAAGGACTGGAATGGGTTTCGTCT ATTAGCGGCAGTGGTAGCGATACGCTCTACG CGGACTCCGTGAAGGGCCGTTTCACCATCTC CCGCGATAACGCCAAAACTACACTGTATCTG CAAATGAATAGCCTGCGTCCTGAAGACACGG CCGTTTATTACTGTACTATTGGTGGCTCGTTA AGCCGTTCTTCACAGGGTACCCTGGTCACCG TCTCCTCA 08A5-9GS-Alb8 75 GAGGTGCAATTGGTGGAGTCTGGGGGAGGAT TGGTGCAGGCTGGGGACTCTCTGAGACTCTC CTGTGCAGCCTCTGGACTCACTTTCAGTAACT ATGACATGGGCTGGTTCCGCCAGGCTCCAGG GAAGGAGCGTGAATTTGTAGGGGCTAGTTGG TGGAGTGGTGGTGCCCCATACTATTCAGACT CCGTGAAGGGCCGATTCACCATCTCCAGAGA CAACGCCAAGAACACGGTGTATCTGCAAGCG AACAGCCTGAGACCTGAGGACACGGCCGTTT ATTACTGTGCAGCCAAAAGGCTGCGTAGTTT CGCCTCCGGTGGGTCGTATGATTACTGGGGT CAGGGGACCCAGGTCACGGTCTCCTCAGGAG GTGGCGGGTCCGGAGGCGGATCCGAGGTAC AGCTGGTGGAGTCTGGGGGTGGCTTGGTGCA ACCGGGTAACAGTCTGCGCCTTAGCTGCGCA GCGTCTGGCTTTACCTTCAGCTCCTTTGGCAT GAGCTGGGTTCGCCAGGCTCCGGGAAAAGG ACTGGAATGGGTTTCGTCTATTAGCGGCAGT GGTAGCGATACGCTCTACGCGGACTCCGTGA AGGGCCGTTTCACCATCTCCCGCGATAACGC CAAAACTACACTGTATCTGCAAATGAATAGC CTGCGTCCTGAAGACACGGCCGTTTATTACT GTACTATTGGTGGCTCGTTAAGCCGTTCTTCA CAGGGTACCCTGGTCACCGTCTCCTCA 08A10-9GS-Alb8 76 GAGGTGCAATTGGTGGAGTCTGGGGGAGGCT TGGTGCAGGCTGGAGGGTCTCTGAGACTCTC CTGTGCAGCTTCTGGAAGCATCTTCAGTATC GCTGCCATGGGCTGGTACCGCCAGGCTACAG GGAAGCAGCGCGAGTTGGTCGCAACTATCAC TGATGGCGGTACGACAACCTATGCAGACTCC GTGAAGGGCCGAGTCACCATCTCCAGGGACA GGTCTGCGAACACGGTGTATCTGGCAATGAA CAATTTGAAACCTGATGACACAGCCGTCTAT TATTGTTATGCGTATCTGCGCTATACAAGCA GAGTACCTGGCGATAACTACTGGGGCCAGGG GACCCAGGTCACGGTCTCCTCAGGAGGTGGC GGGTCCGGAGGCGGATCCGAGGTACAGCTG GTGGAGTCTGGGGGTGGCTTGGTGCAACCGG GTAACAGTCTGCGCCTTAGCTGCGCAGCGTC TGGCTTTACCTTCAGCTCCTTTGGCATGAGCT GGGTTCGCCAGGCTCCGGGAAAAGGACTGG AATGGGTTTCGTCTATTAGCGGCAGTGGTAG CGATACGCTCTACGCGGACTCCGTGAAGGGC CGTTTCACCATCTCCCGCGATAACGCCAAAA CTACACTGTATCTGCAAATGAATAGCCTGCG TCCTGAAGACACGGCCGTTTATTACTGTACT ATTGGTGGCTCGTTAAGCCGTTCTTCACAGG GTACCCTGGTCACCGTCTCCTCA 14G3-9GS-Alb8 77 GAGGTGCAATTGGTGGAGTCTGGGGGAGGCT TGGTGCAGCCTGGGGGGTCTCTGAGAATTTC CTGTGCAGCCTCTGGAAGCATCTACCTTATC AATTACATGGGCTGGTACCGCCAGGCTCCAG GGAAGCAGCGCGAGTTGGTCGCAACGCTTAC TAGTGGTGGTAGTACCAACTATGCAGGCTCC GTGAAGGGCCGATTCGCCATCTCCAGAGACA ACGCCAAGAACACGGTTTATCTGCAAATGAA CAGCCTGAAACCTGAGGACACGGCCGTCTAT TACTGTAATATAGGAGGAACGCTATACGACA GAAGGCGGTTTGAATCCTGGGGCCAGGGGAC CCAGGTCACGGTCTCCTCAGGAGGTGGCGGG TCCGGAGGCGGATCCGAGGTACAGCTGGTGG AGTCTGGGGGTGGCTTGGTGCAACCGGGTAA CAGTCTGCGCCTTAGCTGCGCAGCGTCTGGC TTTACCTTCAGCTCCTTTGGCATGAGCTGGGT TCGCCAGGCTCCGGGAAAAGGACTGGAATG GGTTTCGTCTATTAGCGGCAGTGGTAGCGAT ACGCTCTACGCGGACTCCGTGAAGGGCCGTT TCACCATCTCCCGCGATAACGCCAAAACTAC ACTGTATCTGCAAATGAATAGCCTGCGTCCT GAAGACACGGCCGTTTATTACTGTACTATTG GTGGCTCGTTAAGCCGTTCTTCACAGGGTAC CCTGGTCACCGTCTCCTCA

Example 1. Cloning

Human CXCR7 (hCXCR7), mouse CXCR7 (Open Biosystems) and cynomolgus encoding cDNA (Table B-1) were cloned into pVAX-1 (Invitrogen) and/or pCDNA3.1 (Invitrogen). Transfection of pVAX1-hCXCR7 and pCDNA3.1-human(mouse)(cyno)CXCR7 constructs in Hek293 cells resulted in CXCR7 cell surface expression as shown by FACS analysis using the human CXCR7 specific monoclonal antibody 11G8 (R&D Systems) and a PE-labeled goat anti-mouse IgG detecting antibody (Jackson ImmunoResearch Inc.).

Example 2. Immunizations

For genetic immunization, endotoxin-free pVAX1-CXCR7 plasmid was produced, dissolved to a concentration of 2 mg/mL in 0.9% saline and stored at −20° C. Four llamas (391, 395, 396 and 397) were immunized with 2 mg pVAX1-hCXCR7 via intradermal Jet injection (Akra DermoJet France) for four times with two weeks intervals. Three weeks after the final DNA immunization, the 4 animals received a boost with camel kidney (CAM) cells (Nguyen et al. 2001. Adv. Immunol. 79: 261-296) (2×10⁷ cells) stably expressing hCXCR7. Three llamas (385, 387 and 404) were immunized with four injections of 2×10⁷ HEK293 cells transfected with pCDNA3.1-hCXCR7 with two weeks intervals. From llamas 391, 395, 396 and 397, peripheral blood lymphocytes were collected 4 days and 10 days after the last DNA immunization and 3 days and 9 days after the cell boost. From llamas 385, 387 and 404, peripheral blood lymphocytes were collected 4 and 8 days after the final cell injection. Additionally, a biopsy of the palpable bow lymph node (LN) was collected from each llama via local surgery 3 days after the last cell boost. From all lymphocyte harboring immune tissues total RNA was extracted and used as template to prepare cDNA.

Example 3: Library Construction

Libraries were constructed from immune tissues collected from all llamas. In short, cDNA was prepared from the extracted total RNA samples (example 2) and used to amplify the cDNA repertoire via nested PCR as previously described (WO 02/085945 and WO 04/049794). The PCR products were digested with SfiI (introduced via nested PCR in the FR1 primer region) and BstEII (restriction site naturally occurring in FR4) and following gel electrophoresis, the DNA fragment of approximately 400 bps was purified from gel. The amplified cDNA repertoire was ligated into the corresponding restriction sites of SfiI-BstEII digested phage display vector (pAX50) to obtain a library after electroporation of Escherichia coli TG1. This display vector allows the production of phage particles, expressing the individual VHHs (hereinforth also referred to as Nanobodies) as a fusion protein with a C-terminal Myc-His6-tag (hereinforth also TAG-1 or SEQ ID NO: 71) and with the geneIII product.

Libraries were rescued by growing the bacteria to logarithmic phase (OD₆₀₀=0.5), followed by infection with helper phage to obtain recombinant phage expressing the cloned Nanobodies on tip of the phage as a pIII fusion protein. Phage was stored after filter sterilization at 4° C. for further use.

Example 4 Selections of Phage Displaying Human CXCR7 Binding Nanobodies

Phage from the above libraries were used for selections on hCXCR7 virus-like particles (VLP; Integral Molecular), intact CXCR7 expressing cells, membrane extracts from CXCR7 expressing cells and peptides.

In a first selection round, 10 units of VLPs derived from hCXCR7 transfected HEK293 cells were coated in 96-well MAXISORP™ plate (NUNC®) and blocked with low-fat milk powder (Marvell 4% in PBS). After 2 hours of incubation with rescued phage, trypsin elution (1 mg/ml) was allowed for 15 minutes at room temperature subsequent to 20 PBS washes. Protease activity was immediately neutralized by applying 16 mM protease inhibitor ABSF. The round 1 phage outputs were rescued and a second selection round was performed on 10 or 1 units of plate-immobilized hCXCR7 VLPs. The round 2 phage outputs selected on 10 or 1 units plate immobilized hCXCR7 VLPs were infected into TG1 cells and plated on agar plates (LB+Amp+2% glucose).

Individual colonies of E. coli TG1 infected with the eluted phage pools obtained after selections were picked up and grown in 96-deep-well plates to produce monoclonal phage after addition of helper phage. The production of monoclonal Nanobodies was induced by the addition of isopropyl-b-D-thiogalactopyranoside (IPTG). The perisplasmic fraction containing Nanobodies was then prepared by freezing-thawing of the bacterial pellet in PBS and subsequent centrifugation to remove cell fragments.

Example 5. Identification of CXCR7 Specific Nanobodies by Phage ELISA

From all round 2 selection outputs clones were screened in phage ELISA on 2 units of immobilized CXCR7 VLPs applying 10-fold dilutions of phage supernatant. After incubation with HRP-conjugated monoclonal-anti-M13 antibody (GE, Cat#363761) and several washings, phage binding was revealed using TMB substrate (Pierce). The reaction was stopped with H₂SO₄ and the absorbance was measured at 450 nm using Sunrise TECAN spectrophotometer (TECAN). Nanobodies, showing a minimally 2-fold increased ELISA signal on hCXCR7 VLPs over non-transfected control VLPs, were considered to be CXCR7 specific. CXCR7 specific Nanobodies were sequenced and redundant Nanobodies (identical AA sequence) were removed. This resulted in the identification of 78 unique sequences, belonging to 45 distinct Nanobody B-cell lineages. Phage ELISA data for representative clones from distinct Nanobody B-cell lineages are represented in Table B-7 and indicate that the Nanobodies do bind to human CXCR7 on VLP.

TABLE B-7 CXCR7 screening results-ELISA. Clones CXCR7-LP 2U/ LP Null-LP Fold CXCR7-LP/ with Tag-1 well [OD] [OD] Null-LP 08A05 0.019 0.008 2.4 08A10 0.104 0.006 17.3 14G3 0.316 0.043 7.3 07B11 0.041 0.010 4.1 07C3 0.053 0.012 4.4

Example 6. Identification of CXCR7 Specific Nanobodies by FACS Analysis

Clones representing distinct Nanobody B-cell lineages were tested as periplasmic extracts for their binding to cell surface exposed CXCR7. In this assay, 5-fold dilutions of periplasmic extract were incubated with Hek293 hCXCR7 and Hek293 wt cells. Binding of the Nanobodies was detected using mouse anti-myc (Serotec), followed by anti-mouse IgG-PE (Jackson Immununoresearch). Binding signals of selected Nanobody clones (mcf values and ratios of binding) are represented in Table B-8 and indicate that the Nanobodies do bind to cellular human CXCR7.

TABLE B-8 CXCR7 screening results-FACS analysis. Fold Hek Clones Hek-CXCR7 Hek wt CXCR7/ with Tag-1 Family Llama [MCF] [MCF] CXCR4 08A5 14 396 18621 310 60.1 08A10 20 397 27411 322 85.1 14G3 23 385 45811 381 120.2 07B11 34 395 42877 389 110.2 07C3 37 391 23359 319 73.2

Example 7. Expression of CXCR7 Specific Nanobodies

Selected Nanobodies were recloned in E. coli expression vector pAX100 and expressed as C-terminal linked myc, His6 (hereforth also Tag-2 or SEQ ID NO: 72)-tagged proteins. Nanobodies were also expressed as fusion proteins comprising Alb8 (Nanobody-linker-Alb8-myc-His6) (see sequences SEQ ID NO: 44 to 48—Table B-4) or as tagless Nanobodies. Expression was induced by IPTG and allowed to continue for 4 h at 37° C. After spinning the cell cultures, periplasmic extracts were prepared by freeze-thawing the pellets. Nanobodies were purified from these extracts using immobilized metal affinity chromatography (IMAC) and a buffer exchange to D-PBS.

Example 8. Binding FACS Analysis of CXCR7 Specific Nanobodies

Serial dilutions of purified proteins (concentration range: 400 nM-180 pM) were incubated with stable HEK-CXCR7 cells for 30 min at 4° C. and binding was detected using anti-mouse anti-myc (Serotec) and anti-mouse IgG-PE (Jackson Immunoresearch). The half maximal effective concentration (EC50) values and upper plateau levels of selected clones are depicted in Table B-9. These data confirm the screening data and underscore that the indicated Nanobodies bind to cellular human CXCR7.

TABLE B-9 Binding FACS analysis Clones Plateau with Tag-2 EC50 [mcf] 08A5 8.9 28474 08A10 11.9 34896 14G3 10.2 23807 07B11 30.5 24898 07C3 3.3 33113

Example 9 Nanobodies Compete with SDF-1 for CXCR7 Binding (Displacement Assay)

In order to assess the competition capacity, Nanobodies were evaluated in SDF1 ligand displacement assays using stable NIH3T3-hCXCR7 cells. 24 h after seeding the cells, the cells were pre-incubated for 1 h at 4° C. with a dilution series of purified monovalent Nanobodies and the corresponding C-terminal Tag-2 tagged fusion proteins to the human serum albumin binding Nanobody Alb8 (see Table B-4: SEQ ID NOs: 44 to 48 wherein the polypeptides are all C-terminal tagged with Tag-2). Also reference molecules Mab 8F11 (Biolegend), Mab 11G8 (R&D) and unlabelled SDF1 were included in the assay. Radiolabeled [¹²⁵I]-CXCL12 was diluted and added to the cells to reach a final concentration of 75 pM and cells were incubated for 3 h at 4° C. After incubation, cells were washed twice, lysed with RIPA buffer and the ¹²⁵I signal was measured. Average Ki values and the percentage of displacement relative to the displacement of cold SDF1, are shown in Table B-10. The competition of tested Nanobodies and 8F11 Mab is between 73 and 83%, relative to competition with unlabelled SDF1. This level of displacement correspond to a 100% blocking of the CXCR7 protein, as the remaining SDF-1 binding is believed not to be CXCR7 mediated, but due to the SDF-1 interaction with heparan sulfate proteoglycans. Fusion to the human serum albumin-binding Nanobody Alb8 has no significant effect on Ki values.

TABLE B-10 Displacement assay SEM Average Ki SDF-1 Clones whole 3T3 displace- SEM displace- with Tag-2 [nM] ment n Ki ment (%) 08A5 13.6 77 8 2.5 6.4 08A5-9GS-Alb8 17.9 1 08A10 12.1 75 8 1.8 3.3 08A10-9GS-Alb8 14.1 1 14G3 3.0 73 6 0.6 3.3 14G3-9GS-Alb8 3.5 1 07B11 96.1 75 2 1.3 1.5 07B11-9GS-Alb8 82.4 1 07C3 12.2 78 2 6.6 15.0 10.2 1 SDF1 0.121 100 15 0.019 0.0 11G8 Mab 4.4 24 3 2.7 2.0 8F11 Mab 5.9 73 6 2.4 4.1

Example 10 Nanobodies Compete with SDF-1 for CXCR7 Binding (FACS Assay)

The potency of Nanobody 7CXCR07C3 and Mab 8F11 (Biolegend) to compete with SDF1 was evaluated in competition FACS with HEK-hCXCR7 cells. Cells were incubated simultaneously with 4 nM biotinylated SDF1 (R&D) and with diluted test molecules, for 2 h at 4° C. Binding of biotinylated SDF1 was detected using streptavidin-PE. Competition curves are depicted in FIG. 1. In this assay, Mab8F11 and 07C3 competition is complete (>95%), relative to competition with unlabelled SDF1, underscoring the complete inhibition of the SDF-1-CXCR7 interaction.

Example 11 Nanobodies Compete with 11G8 Mab for CXCR7 Binding (FACS Assay)

The minimal epitope of Mab11G8 is known to be F₁₄SDISWP₂₀ located at the CXCR7 N-terminus (see e.g. WO2008048519). Competition of Nanobodies, Mab 8F11 (Biolegend), Mab 11G8 (R&D) and Mab9C4 (MBL) with Mab11G8-APC was tested in FACS analysis. Cells were incubated simultaneously with 20 nM Mab11G8-APC (R&D) and with diluted test molecules for 2 h at 4° C. Competition curves are depicted in FIG. 2. The level of competition with Mab11G8-APC ranges from ˜20 to 100% suggesting that the respective Nanobody epitopes match to a high degree (high % of competition) with the 11G8 epitope or to a low degree (low % of competition) or induce allosteric changes affecting the 11G8 binding. This data indicates that the selected Nanobodies bind to divergent epitopes.

Example 12 Mouse/Cyno Cross-Reactivity

Taking into account CXCR7 extracellular domains Met₁-Lys₄₀, Ser₁₀₃-Lys₁₁₈, Lys₁₈₃-Glu₂₁₃ and Leu₂₇₃-Ala₂₉₆, only 9 residues (Leu₃, Ser₉, Phe₁₄, Ser₁₈, Met₃₃, Asn₃₆, Arg₂₈₈, His₂₉₁ and Ala₂₉₂) differ between human and mouse CXCR7. HEK293 cells transfected respectively with pCDNA3.1-hCXCR7 and pCDNA3.1-mCXCR7 were used to test cross-reactive binding of Nanobodies to mCXCR7 in FACS analysis. Cells were incubated with 32 nM Mab 11G8 (R&D), Mab 9C4 (MBL), Mab 8F11 (Biolegend) or with 800 nM Nanobody for 2 h at 4° C. Nanobody binding was detected using mouse anti-myc (Serotec) and anti-mouse IgG-PE (Jackson Immunoresearch) and Mab binding by goat anti-mouse IgG-PE (Jackson Immunoresearch). Nanobodies 08A10, 14G3, 07B11 and Mab9C4 are not cross-reactive to mouse CXCR7, indicating that at least one of the nine divergent residues is crucial for the binding to human CXCR7. Nanobodies 08A5 and 07C3 partially cross-react with mouse CXCR7, indicating that at least one of the nine divergent residues is involved in binding with human CXCR7. Mab8F11 and Mab11G8 are cross-reactive to mouse CXCR7, indicating that none of the nine divergent residues is involved in binding with human CXCR7. Together, this shows that all Nanobody fingerprints differ from Mab8F11 and Mab11G8 fingerprints.

Cross-reactive binding to cynomolgus CXCR7 was assessed in the same way. Taking into account CXCR7 extracellular domains Met₁-Lys₄₀, Ser₁₀₃-Lys₁₁₈, Lys₁₈₃-Glu₂₁₃ and Leu₂₇₃-Ala₂₉₆, only one residue (Leu₅) differs between cynomolgus and mouse CXCR7. Not unexpectedly, Nanobodies 08A10, 14G3, 707B11, 08A5, 07C3 and Mab9C4, Mab8F11 and Mab11G8 are all cross-reactive to cynomolgus CXCR7.

TABLE B-11 Cross-reactivity to mouse CXCR7 Clones Mouse Cyno with Tag-2 Family Llama crossreactivity crossreactivity 08A5 14 396 Partial Yes 08A10 20 397 No Yes 14G3 23 385 No Yes 07B11 34 395 No Yes 07C3 37 391 Partial Yes 8F11 Mab Yes Yes 11G8 Mab Yes Yes 9C4 Mab No Yes 

We claim:
 1. An immunoglobulin single variable domain comprising an amino acid sequence with the formula 1 FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4  (1); wherein FR1 to FR4 refer to framework regions 1 to 4 and are framework regions of an immunoglobulin single variable domain; and wherein CDR1 is the amino acid of SEQ ID NO: 10; and wherein CDR2 is the amino acid of SEQ ID NO: 20; and wherein CDR3 is the amino acid of SEQ ID NO: 30; wherein said immunoglobulin single variable domain specifically binds to human CXCR7.
 2. The immunoglobulin single variable domain according to claim 1, wherein the framework regions (FRs) have a sequence identity of more than 80% with the FRs of SEQ ID NOs: 4 to 8 (FR1), 14 to 18 (FR2), 24 to 28 (FR3), 34 to 38 (FR4).
 3. A polypeptide comprising an immunoglobulin single variable domain of claim
 1. 4. The polypeptide according to claim 3, wherein the immunoglobulin single variable domain is selected from the group consisting of immunoglobulin single variable domains that have an amino acid sequence with a sequence identity of more than 80% with the immunoglobulin single variable domains of SEQ ID NO:
 40. 5. The polypeptide according to claim 3, additionally comprising at least one human serum albumin binding immunoglobulin single variable domain and optionally comprising a linker selected from the group of linkers having an amino acid sequence of SEQ ID NO: 49 to
 58. 6. The polypeptide according to claim 3, additionally comprising Alb8 having an amino acid sequence of SEQ ID NO: 2 and optionally comprising a linker having an amino acid sequence selected from the group of linkers having an amino acid sequence of SEQ ID NO: 49 to
 58. 7. The polypeptide according to claim 3, wherein the polypeptide is selected from the group consisting of polypeptides that have an amino acid sequence with a sequence identity of more than 80% with the polypeptide of SEQ ID NO:
 45. 8. A nucleic acid molecule comprising a nucleic acid sequence encoding for an immunoglobulin single variable domain according to claim
 1. 9. A pharmaceutical composition comprising an immunoglobulin single variable domain according to claim 1; and optionally a pharmaceutically acceptable excipient.
 10. An immunoglobulin single variable domain according to claim 1 for use in cancer and/or inflammatory diseases.
 11. An immunoglobulin single variable domain according to claim 1 for use in rheumatoid arthritis.
 12. An immunoglobulin single variable domain according to claim 1 for use in multiple sclerosis.
 13. Method for producing an immunoglobulin single variable domain, said method at least comprising the steps of: a) expressing, in a suitable host cell or host organism, a nucleic acid or nucleotide sequence according to claim 8; optionally followed by: b) isolating and/or purifying the immunoglobulin single variable domain.
 14. A polypeptide comprising an immunoglobulin single variable domain of claim
 2. 15. A nucleic acid molecule comprising a nucleic acid sequence encoding for a polypeptide according to claim
 3. 16. A pharmaceutical composition comprising a polypeptide according to claim 3 and optionally a pharmaceutically acceptable excipient.
 17. A polypeptide according to claim 3 for use in cancer and/or inflammatory diseases.
 18. A polypeptide according to claim 3 for use in rheumatoid arthritis.
 19. A polypeptide according to claim 3 for use in multiple sclerosis.
 20. Method for producing an immunoglobulin single variable domain, said method at least comprising the steps of: a) expressing, in a suitable host cell or host organism, a nucleic acid or nucleotide sequence according to claim 15; optionally followed by: b) isolating and/or purifying the immunoglobulin single variable domain. 